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USB KVMs Compared
EconolineCrush writes "KVM switches have always been a great way to control multiple machines, and now they're coming with all sorts of cool USB peripheral sharing and audio switching functionality. The Tech Report has a compared a couple of the newest KVM switches from Belkin and IOGear that're worth a look if VNC just doesn't do it for you."
have lots of problems. I've had 3 at work, they all have had the same scenario, they'll drop my mouse, perform actions I didn't do, quit working and until I power cycle it. I find VNC or RDP to be much easier, the only machines I connect to are servers, home and work. If I want to play a game, I'll use my high end workstation, but for all server tasks, It's all about VNC/RDP it has a lot less issues.
--fetch daddy's blue fright wig, i must be handsome when i release my rage
Forget USB, I want a KVM that doesn't make my video cards output look like crap on my LCD... Why don't the manufacturers care about video quality at 1600x1200??? Just because I want to run multiple machines from one keyboard / LCD, doesn't mean that I'm running at VGA resolutions...
---
Programming is like sex... Make one mistake and support it the rest of your life.
can't use it for my 486 terminal server. bastards!
IP bananas are bad.
I've got one of these hooked up betwen my old ass G3/233 (with Mac OS X 10.1.5 and a combo USB/Firewire card, which works great) and my XP box. Plug commonly used devices into the extra ports on the front, like my Epson printer and my Handspring Visor, and it's good to go. I haven't had one single problem with the unit so far, and there was even a $20 rebate, so it was under $100 too. :-)
Forget KVM switches, VNC, RDP, or anything else that takes you away from a shell prompt. OpenSSH is your friend. Your keyboard. Your display. Your $ prompt. Available at web sites while source code lasts.
KVMs are good, and they certainly have a variety of specialized uses, but they're not versatile enough, in my opinion. For example, in situations where two computer might need to both be used at once. What do you do then?
I've been looking around for solutions to this problem, because I've been thinking of opening a cybercafe, and I found something called BeTwin.
BeTwin is like the inverse of a KVM switch. Instead of having one keyboard, monitor, and mouse control one of a bunch of machines.. it turns a single machine -into- the bunch of machines.
Licences are $80 a head, and you can have up to 5 people independently using a single Windows 2000/XP machine just by plugging 5 USB keyboards, 5 USB mice, and 5 graphics cards into a computer (5 USB speakers too, if you think the USB bandwidth will take it!).. absolutely ideal for cybercafes where processing requirements on each station are low.
I have decided to go with the Linux route, rather than pay these fees, but thought I'd share it anyway.
mogorific carpentry experiments
I don't know why I was IP banned, I think that it was cos I refused to eat Rob's special taco. Oh, well, I've still got 5 more IP banks that I can switch between....
I use KVM switches at work and wish I had one at home. The ones I use are fairly expensive (Blackbox... they make lots of server products) and still leave something to be desired. On high resolutions, it takes a couple of seconds to switch between machines and even after paying so much, you can make out that the image is a little blurred on a 21 inch LCD (from Dell). And most of them dont work too well with laptops.
That said and done, I have to add that they are indespensible. Its amazing how much time it saves especially with keyboard shortcuts (you press Control-Control to get to the KVM and then a letter for the computer you want to switch two). Plus its essential in server rooms where these boxes can be cascaded to 64 or 128 machines. Now if only the good ones were a little bit more affordable for the rest of us....
I have a run of the mill PS/2 KVM (Belkin Omni Cube) that switches between my Sparc and my Linux laptop. I had to shell some $$ for a ps/2 converter for the Sparc but it has just worked for over 2 years, no sweat.
And it has seen it's share of Quake.
I do not use it for switching the video -- the Sun Monitor (behemoth) has 2 inputs.
Great, more scope to control (or hide) all those pR0n downloading/watching sessions.
Are you local? There's nothing for you here!
I have always used my ps/2 or parrallel ports when I had the chance. I never really realized why most insist on usb. It isn't as if the mouse goes "faster" or little lights on the keyboard are prettier while using USB over ps/2. My logic has always said, why use up 3 of my computer's 4 USB ports on something that I already have a plug for anyway. Why let the others go to waste?
Buy another keyboard, mouse, and monitor. That's not a problem KVMs were designed to fix. Think instead about the server room full of machines. Now, what do you do if/when you actually have to access one of those directly (ie, from the console, not over the LAN) (don't focus on the wrong part here. There are reasons you may need to directly access the console, like say your NIC died, or you're in the process of installing the OS. The reason here doesn't matter, what matters is that there are reasons why you would need to access the console directly rather than via ssh or vnc or X or terminal server or whatever)? Wheel out the cart with the monitor and keyboard? Or just go sit down at the station where you already have the monitor, keyboard, and mouse setup, with all the machines connected to Cybex KVM switches (the heavy-duty server room KVM switches are quite a bit different than the 2-port or 4-port switches you'll use at your desktop)? With the latter option, you never have to dig around behind a machine for the cables, or try to get back there to plug in that monitor on the cart. Just hit the hotkey, pick the machine you need to access, and you're there at the console.
If you only have two or three machines that all need audio, it's probably a better idea to either buy a small mixer board (the slightly expensive or skill-required choice) or run them all through one another (the cheapass choice.) If you have two machines there's really no reason not to do this, unless you plan on turning one off occasionally while using the other- but if you're a KVM kinda guy chances are you leave the damn things on eternally. If they're close enough to one another and you don't use cables that are too long or loop around other things- one could use a 8 inch mini cable to connect a pair of towers sitting next to one another- you won't have any signal problems.
The clear choice seems the IOGear device- it comes with cables, has OSD, and does not hail from the nauseating Brushed Metal Plastic Alien Bubbles school of design.
What we call folk wisdom is often no more than a kind of expedient stupidity.-Edward Abbey
KVM switches are okay if you're just trying to avoid having more than one monitor for a couple of boxes you sit in front of, but they suck for managing a lot of hosts in real production work. I find that using a PC Weasel and a terminal server works a lot better than a KVM switch for remote management of Unix boxes running on PC hardware. KVM switches are okay some of the time, but PC Weasels rock!
What do you use when even an 8-port KVM isn't enough? I'm thinking of a large datacenter scenario like (bring on the flames) the setup in that new Dell commercial with the full racks of 2U servers and just 3-4 screen/keyboard stations.
Obviously remote X sessions/x0RFB/SSH or Win* terminal services/VNC would work, but there are some situations that you just need a direct connection.
I find that the quality of the video signal out of a KVM is often subpar. It doesn't even have to be in 1600 x 1200 resolution. At work my 1024 x 768 display which looked great when the monitor was driven directly looked fuzzy when it had to go through that extra bit of circuitry. Is there any way around that where I can still get multiple machines with one set of I/O devices?
Most of those lowend KVM switches dont work worth a damn. Its usually the highend ones made by companies like Raritan that actually work well (besides the occasional PS/2 mishaps). As far as USB... I've never owned a system where all the USB devices were stable in the first place, so I cant really imagine having a USB KVM. Sounds like a nightmare to me!
I use an Avocent SwitchView DT KVM in my home server rack right now, but it still necessitates the need to be physically at the server rack. The server rack is in a climate controlled room downstairs, but my home office is upstairs.
Ideally, what I would like to do is put ALL my computers (including my development workstation) in a new rack downstairs, so that all I have on my desk is my monitor, keyboard, mouse and speakers. A perfectly quiet office would be so nice. The problem is, how do I run video from the downstairs rack to my office (easily a 40' run)?
Any suggestions?
The ones I've used (genie) make the most anoying beeping noise made by a piezo thats surface mounted so u can't just cut the lines to it. VNC is still the only way for me. Well and X and BO2K of course :)
"Never trust a computer you can't throw." -- The Mac
I tried several of these a year or so ago. The best of the bunch was Linksys. No ghosting, cables included, switch from the keyboard or manually and no power supply needed. I hope they come out with USB on a newer model.
I'm kind of surprised that most new keyboards and mice are USB instead of PS/2. USB is a more versatile standard, sure. But it's not like mice and keyboards actually take advantage of it. I've never had any problems getting a PS/2 peripheral to work on any computer under any operating system. This is the way it should be. USB just unnecessarily complicates things in my opinion.
I've got a PS/2 KVM and trying to figure out how to get the thing to work with a mac is quite an exercise. I would love for this machine to have PS/2 ports. I guess apple just wanted us to be able to plug our mice into our keyboards. Ok, rant mode off.
The article states:
Unfortunately, both of these switches require large, boxy power adapters, the kind that don't tend to fit well in most surge protectors. Ideally, I'd like to see power pulled directly from one of the connected computers, but I'd settle for a power connector that moves the box away from the plug itself.
Perhaps my version of the Belkin KVM switch is different from the one they reviewed, but mine requires no external power. It works exactly as they wished it would... using power from the systems themselves.
I have a Windows PC using PS/2 plugged into port 1, an Apple G4 using USB into port 2, and a Linux box using PS/2 in port 3. The keyboard and mouse are PS/2 and the Belkin box effortlessly translates between them.
The problems they mention with USB peripheral disconnect is likely because the reviewer has connected the USB peripherals to the keyboard. You have to think of the KVM as its own USB device and not a hub. It's a KVM switch not a KVM-CD Burner-Digital Camera switch.
I can't comment on the other switch they review, but I love my Belkin KVM switch and I'd recommend it, especially if you have a mixed installation as I do. It works great with very few problems.
All opinions presented here aren't mine.
It works pretty well, though compared to PS/2 switches, the re-detect for USB mouse and keyboard seems longer.
Be careful!
All the units besides the IOView degrade the video quality, I understand from long conversations with sales people. The IOView, with a Hitachi Elite 751 19 inch monitor and a Matrox G-450 video card at 1600 x 1200 and 75 Hz, actually gives slightly better quality. Odd result, I know, but I'm testing the IOGear MiniView SE 4-port as I type this.
The Tech Report article about 4-port units says, "The other units lack explicit video signal enhancement features, but their quality was the same on both a 17" Trinitron and a 19" NEC AccuSync 95F. Note that this does not mention the video card or the resolution or the refresh rate, indicating that the reviewer was probably not thinking that these were critical. Also, many people are just not good at seeing degradation.
The IOGear MiniView SE 4-port has a VERY funky way of switching between computers. One way, to press a control key twice, is okay, but only goes to next computer in line. The other is amazingly foolish:
[alt]+[ctr]+[shift]+[1 or 2 or 3 or 4]+[Enter]
(See page 14 of the MiniView SE 4-port manual (NOTE:
According to Samantha Martinez of KVM Switches Online (Samantha@kvm-switches-online.com Phone: 303-604-0237 Fax: 303-604-0724), "The only manufacturers that hold that resolution at that refresh rate are Aten/IOGear and Avocent." (They don't sell the Belkin unit, apparently. Aten makes IOGear. You can buy Aten units directly, but they are a worse buy.)
Note that you get 2 4-foot cables and 2 6-foot cables with the MiniView, not 4 6-foot cables.
I just finished returning the Belkin switch they reviewed here. I found it to be unusable, because of some major shortcomings.
The first thing was that it didn't work with my keyboard (logitech wireless). The F7 key was useless when plugged into the KVM. This was relatively minor, and they promised a firmware upgrade to fix it. Also, for those that care (I'm not one of them) the "internet keys" don't work.
The other problem I had was also keyboard related. The KVM has a keyboard emulator, which sends keyboard events to the computer, after receiving them from whatever keyboard you have plugged in. If you hold down a key for 3 seconds, the keyboard emulator fakes a key release. So scrolling stops after 3 seconds, and if you're ctl-clicking to select stuff, and you take more than 3 seconds to do it, suddenly the ctl-key is no longer pressed down, and you select just one item. I got the impression that this wasn't going to be fixed in firmware, but rather in the next revision of the product.
Also, the response time was sluggish at best, typing felt like i was in an ssh session over a slow link. Oh, and keys stuck sometimes.
I was planning on getting the IO Gear one instead, as I am told it doesn't have the same shortcomings. Here's hoping.
I have used switches by Belkin, IOGear, Cybex, and a few others and they aren't even close in quality.
Only the IOGear does not display any video ghosting. IOGear video is rock solid with no fuzziness.
I switched to USB after I saw that IOGear uses 'USB sniffing". This neat feature eliminates that 3 to 4 second delay that every other USB KVM has and makes the switch as responsive as a PS2 switch.
IOGear has top quality stuff but their cables are a bit expensive.
The scroll lock hotkey on the Belkin's can cause the console to get stuck in linux, sometimes you have to hit the button on the KVM to unfreeze it - which can be a pain if you plan on only using the hotkeys and have the KVM in a out reach spot on your desk.
The belkin SOHO series (which I am using now) don't seem to reset PS/2 mice as reliably as the older Omnicubes (which I also use). Although, you don't need AC power for the SOHO series (it will draw power from keyboard ports). I had to return two units (over the course of 1.5 years) that would change channels (with loud beeps) in the middle of the night randomly - even though the PCs were off and wouldn't stop until I unplugged every single cable (including monitor). Adding an AC adapter from a spare omnicube fixed that problem.
Belkin does have a 3 year warrenty on their KVMs though, which has proven helpful for me.
Ability to hotswap? USB keyboards with USB hubs in the back of them (like the MS Natural Keyboards)?
My question is: WHY did everyone switch to PS/2 in the first place? The old RS-232(?) ports could be hot-swapped at will. What POSSIBLE benefit could there be in switching to a protocol that requires a reboot to "re-capture" the input device if the connection is lost?
I've been wondering about this for years, and never heard a satisfactory answer. Anyone know?
--jrd
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Are there any KVM switches that uses digital video? It seems it would be better (quality-wise) to go digital all the way, especially in this kind of application.
So what is the Linux equivalent of this inverse KVM software?
Matter of fact: the refresh rate of usb mice is higher, so it really reacts faster. Ask any quake player...
I use the Iogear Miniview (2-port, CS-102U) everyday to switch between my Mac and my PC (W2000 and RH7.2). It works great, didn't cost much compared to the 4-port versions and comes with good cables. The user manual could be written by Dilbert as there's only one button to press.
I can't see a difference in the video quality (but I can't remember how it was before either...).
Anyway, a great buy for SOHO. And I'm not working for them...
Seriously.. you only have to feed them bananas. They can do the cable hooking up for you - no need to leave your seat.
.. MCSE...
Some of them come with qualifications
This is NOT a suitable topic for SlashDot. This is so totally non-informative (what, keyboard switches? Wow, that's revolutionary new technology that's going to change the lives of 5 billion people!), I can't believe it gets posted.
Don't believe the hype. The guy asking specifically mentioned LCD screens - and they tend to look like hell when you put them through a KVM, especially one of these low end KVM switches. The reviewer was using a CRT screen, unless I'm mistaken.
I tried the previous Belkin USB KVM. It sucked. Apart from failing to switch smoothly at all - the keyboard would constantly disappear on switching and then I'd have to actually move it to another port to get it to work - the video signal was terrible. I was running at 1024x768@70Hz. It was blurry as hell.
I contacted Belkin to tell them it was the least impressive product I'd ever bought, detailing my problems.
On the monitor front, they replied that the switch was not designed to be used with LCD screens, which was why the quality was so bad.
Seriously, when you're used to pin sharp LCD displays, putting them through a KVM and turning them into something that looks like a 6 year old CRT is not such a great idea.
Maybe Belkin have fixed this issue with the new one, but bear it in mind if you have an LCD screen.
I actually have two monitors and one kbd/mouse, and use a simple Belkin no-frills USB switch with the kbd/mouse. It works like a charm - mainly because I don't think it tries to be too clever.
Oh yes - the KVM also looked rubbish on my CRT monitor too - but I traced this to the 'official' Belkin VGA cables - they sucked too. Replacing them with other (not expensive) makes of VGA extension leads improved the video quality on the CRT enormously. This was trivially proved by just using the leads as extension leads, taking the switch out of the equation. When using the Belkin leads, video quality was crap. Again, maybe they've fixed that now - I don't know - but it's something else to be aware of.
Tim
No reason - in your case don't switch. But future PC designs probably won't have the PS/2 port, so if you're buying new keyboards and mice then it makes sense to buy USB variants.
At the moment, connectors are simply a mess. Just think of the number of different types on a typical, well-equipped PC:
- PS/2
- USB (sometimes split into 1.1 and 2.0)
- Firewire
- Serial
- Parallel
- RCA sockets
- MPU-401 compatible (gameport to most, MIDI port to me
- S/PDIF
- VGA
- RJ-45
- RJ-11 for modem
Don't now about DVI - does it take a different connected to VGA? If so, add DVI to that lot. Gives you eleven (twelve including DVI) different connecters excluding the power cable, and we haven't started on the internal mess yet.On the whole, standardising on the smallest number of connectors possible is a good thing. I'd personally like to see USB die as well and everything go firewire (and no, I'm not on a Mac), but that's a pipe-dream that isn't going to happen.
Cheers,
Ian
Simply buy an IP KVM which supports multiple simultaneous sessions.
Didn't see any posts about the StarTech KVM's. Got one and it's great, except that I can't use escape during the BIOS memory-check for some reason... Mine's still PS/2 and I hope vendors will switch to USB or FireWire soon and get rid of all the old PS/2/serial/parallel ports. I want a motherboard with just PCI, AGP, Serial-ATA and USB(or FireWire).
Everything blackbox has is all another brand of switch with the blackbox logo on it and sold on higher prices. For example, their matrix switch to hold 2 users is a Rose-Technology switch. It took me a long time to find it what kind of switch they were using and they seem to use Minicom and Rose (mainly). The only difference is the price and the ugly black logo put on another product.
If you are in need with a new switch you should look to these because the switch has up to 40m support without quality loss of the image; can use a line extender up to 300m and has a exclusive feature to protect your ports by groups and users.
For example user A can access all servers while user B can only look to server 1 and 2, user C can control server 1, 3 and look to server 8 but not control it,
It also has OSD and is expandable to more of these units.
The more-expensive unit (rack unit) is expandable in any way.
Look at the pdf for more info.
The 2 users * x ports
The 4 users * x ports
The high-end series.
--- I am known for the ones who want to find me on the net. Is that a privacy risk or a privilege? One might wonder..
It's rather nice to be able to put your monsterously loud 1337-computer in another house, but how do you handle removable media (cd/dvd/disk)?
We do not live in the 21st century. We live in the 20 second century.
"...average joe user looking to build a cluster or distributed computing system. "
umm.. right.
While these are great products, what they dont tell you is there are several problems that they have never bothered to correct.
The biggest of these is that they have MAJOR problems working with some COMPAQ servers. Even the newer models with their much toted, Flash upgrade port are useless because this is a known hardware level problem that exists in all generations of belkin KVM switiches.
Its been a known problem for a long time, I'm just annoyed that they dont warn about it.
Just my two cents.
Remember Belkin+compaq=non functional
"We deal in lead" - Roland of Gilead
like the belkin matrix? that can connect 2 displays to any of 128 computers?
I've got a Belkin 16 port USB/PS/2 switch that works great, except for when I attempt a network boot. It seems the PC's don't pick up the KVM switch during boot and you can't hit the F12 button in time. However, a USB keyboard hooked directly into the PC works fine. It's not a problem unless you're looking into legacy free machines that don't have PS/2 ports.
Anyone know of any solutions? Compaq and Belkin blame each other....
Sit back and relax as Windows 98 installs on your computer.
Does anyone know of a KVM that supports the digital adapter for the new Apple LCD monitors? I'd especially like one that can handle conversion for conventional, analog display adapters. I have three Linux systems on PC hardware working on an older Belkin KVM. One of the things holding me back from buying a new dual-processor G4 tower with a beautiful 17" flat panel is the integration issues with my current environment. I don't want two sets of keyboard, monitors, and mice.
Thanks...
When I got a couple of new to me PowerMacs I had to find a way to hook up my existing 2 PowerMacs and 1 PC with the new machines.
After looking and looking, I found the Dr. Bott MoniSwitch Pro 8 Port USB KVM switch. It wasn't cheap ($400), but it works great. I wish it had keyboard shortcuts to switch CPUs (it has a dial you turn to select a computer) and the VGA connectors on the back are Male, contrary to every other KVM I have seen where the connectors are Female.
I would highly recommend it, though, to anyone who is looking for a USB KVM solution for more than 4 machines
I mean they do hae USB adapters for PS2 ports. I use 8 and 16 port KVM's for multiple platforms. Unless they offer some added benefit, why spend the extra money to get one?
I have the same unit. Inclusion of cables, and a few favorable comments on USENET, won out over Belkin. We use BlackBox at work, but that's more than I want to spend at home.
The biggest problem I've had so far is that the keyboard isn't responsive enough for action games. I can type fine, but I can't play Max Payne. I'm still investigating this problem, as it could be the USB adapter I'm using on the PS/2 keyboard.
Two of the computers had no problem using the keyboard and mouse: an Intel 810E running Linux and an Alladin V running Windows and Linux. The third system, a VIA KT133A, is not as happy. Windows 98 did not recognize the keyboard or mouse. I had to connect a keyboard directly to dismiss the "mouse not detected" message and install drivers. I have yet to get Linux to recognize the keyboard or mouse on this system.
Because of the mention of VNC I thought I would give a post of what I want. Any hardware companies reading this?
Ok, here goes. I want a KVM switch with a built in VNC server! It should have a ethernet port and get an IP addess. Then it could use a differnet viewport for each device. Man, this thing would make remote administration a breaze!
Example from real life. A client has a group of 4-7 servers in their server room/closet. You hook them up to a KVM switch(you should already have them on one). You forward all the neccesary ports(assuming you are using private addresses behind a NAT router, which you should be) to the ip address of the switch and viola, remote administration of all your servers!!! Now, there are security concerns to be sure, but no more than using PcAnywhere and RDP or ICA. I'd buy them for most of my client's sites.
What do you guys think?
Daniel
Is it just me, or does the Belkin have FireWire ports too? Sure looks like it in the photos.
The IOView, with a Hitachi Elite 751 19 inch monitor and a Matrox G-450 video card at 1600 x 1200 and 75 Hz, actually gives slightly better quality.
OK, I know you qualified this as an 'odd' result, but can someone explain how this could possibly be true ? If you're plugging the computer into the switchbox, the signal the SWITCHBOX is getting is the same signal the monitor would be getting if you didn't use the switchbox. But you're running more cable between the switchbox and the monitor and you have a device in between, to boot.
So how is the switchbox able to increase the video quality without introducing its own noise ?
The KVM switch we use is hooked up to a companion product from the same company, which converts the video signal to a very decent VNC server. I can connect to this VNC server, and using keyboard shortcuts, see exactly what is on the screen for any of the servers in the farm. I can even reboot a server, and watch it go through POST, etc, even stop it and interact with the BIOS menu... all because of how VNC is setup.
Check out StarTech KVM products. I think you can use that VNC box with other companies' KVM's also...
"And like that
Paragon KVM from Raritan is IMHO the best KVM ever created. 8x32 support on one kvm... Sun / PC / USB / terminal support all from one KVM. It uses CAT5e for the cables between the KVM and the systems. It is reliable and it runs a LONG distance. It has user log in support and you can allow or disallow access to machines with it. They have a remote access unit that connects to the KVM and gives ethernet ISDN modem support. (I havent used that but I guess its a lot like hardware VNC in the KVM)
They are about 4K each for 8x32 but TOTALY worth it for cable managment, ease of use, and mixed environment support. (not to mention they are only 1u each.)
A lot of praise is being said about the IOGear USB KVM switches. I personally have a their 4 port MiniView. It's advertised as being "Linux compatable".
.18-5), the usb kernel modules does not like it at all. (Mind you, the 2.4.19.rc-3 patch does have a kludge for the Aten/IOGear USB switch, but I haven't played with it yet, so again, YMMV).
It's a classic case of when someone says YMMV, and you find out that sure enough, your mile is not == 5,280 feet.
For instance, with a stock RedHat 7.3 kernel (2.4.18-3 through
Their advertised keyboard hot-switching doesn't apparently like the MS Internet Keyboard Pro, either. So, it's either manually reach over to the KVM and select the system you want, or curse at the folks at IOGear who are patently clueless.
Otherwise than that, works great on the standard Windows boxes and the Mac platform.
But, for now, it's pretty much SSH/X-windows forwarding to use that Linux box.
I agree about the cables. Why did IOGear put the keyboard and mouse cables in the front? What could they possibly have been thinking?
There are a lot of Chinese, who work for these Chinese companies, who own only a bicycle, two pairs of black pants, and three white shirts. They are not the sort to worry about convenience in a product they will never own. (I've spent time in Taiwan buying computer parts.)
I have two desktops where I work and my boss gave me a KVM to switch between the two. As soon as I hooked it up, I noticed that the image quality was poor, and extremely blurry. Since then, I have noticed this same distortion on everyone elses setups that I have seen. Is there an alternative or a better KVM switch that will have the same clarity as a monitor not hooked up to a KVM switch? I was using a Belkin switch, but the poor quality was enough for me to stop using it and just resort to manually moving the cable back and forth.
I was/am interested in getting a USB KVM for my Sun Blade 100 at work, so we ordered one (a Belkin Pro series), but get this: You can't have the mouse/keyboard on the Sun not plugged in as root devices on boot. For those of you that may not know, Plus the 1280x1024 picture on my monitor got flickery. Argh.
I'll keep looking, but at the moment I'm sticking with 2 monitors, 2 keyboards, and 2 mice... Most salient point is that USB support on the SunBlade 100 isn't up to par (along with CDROM support). You get what you pay for I guess, but we can hope that if Sun makes a sequel to the Blade 100 it will fix these dumb problems.
If anyone knows of a USB KVM that lets two devices pass through straight (ie doesn't act like a hub) I'd appreciate hearing about it.
Peace or something like it,
Rich
Has anyone out there used either of these KVMs w/ a PC (running linux or windows) and a Mac running OSX? I'd like to find out any problems people have had w/ them before purchasing a device like this for on of my users..
-Mike
Your problem with anger is by far the biggest issue here.
I don't think the company will think the way you think. After they get 100 calls from Slashdot people wanting KVM's, will the president worry about a rare situation in which some very foolish spammer uses her email address? I doubt spambots try to harvest email addresses from Slashdot, because they would get almost nothing that way, and Slashdot people know how to protect themselves (Spamcop).
(I don't have any connection with the company.)
The biggest reason that some people would not use a KVM is because they would fear video degradation, which is definitely an issue with some units, as Samantha indicated.
A friend pointed out that there must be something imperfect in the way the Matrox card outputs its signal. Also, the difference is very small (but unmistakeable). I did not try the IOGear with the latest Matrox cards (G-550). I was too busy at the time.
Noise is not an issue here. The signals are very high level.
Mainly because, back in the day, serial mice grabbed either IRQ 3 or 4. This was painful, especially if you need to have more than 2 serial devices in your machine, because plug and play was still pretty rudimentary at that point if you were using Windows 95, and not available if you were stuck in Dos/3.11. Sure, you could occasionally find serial cards that made COM3 == IRQ 9, but you were lucky to find software that could be adjusted to take advantage of that.
Putting the mouse on a PS2 port actually made things a good deal easier at that point.
I didn't try the Belkin because Samantha told me about this.
I agree about the Aten form facter. Amazing mistake.
There is an issue with IOGear changing the model without changing the model number, so make sure you get fresh stock. Order from a big supplier.
I find some keyboards hang when on cheap KVMs because there is momentary power sag when workstations are shifted. I put a big electrolytic capacitor across the power lines to my keyboard to prevent this problem. I don't really see the point of switching audio lines; I'd prefer to hear audio from all boxes coming together through some sort of mixer - ideally one I can control computationally and manually. Does anyone know of a mixer ideal for this purpose?
The flag just makes more sense than the constitution. - Judas Gutenberg
Personally, I liked that the Belkin did not come with cables. Although that sounds strange at first, I realized that the odds of Belkin supplying the exact cabling that would work in my installation (factors include length, connector types (USB vs. PS/2), quality) were nil.
I would, however, strongly suggest paying the extra bucks for high-quality video cables to connect boxes with graphics displays. I upgraded from a Rat Shack VGA extender cord to a Belkin Pro-series integrated cord, and the difference in picture quality at 1600x1200x85 is noticeably better. I'd almost gotten used to the slight ghosting, but the Belkin cable cured that completely. Feel free to stick the cheap cables on your servers' text displays, though.
Dewey, what part of this looks like authorities should be involved?
It was cheap when cheap mattered, and it replaced a connection without changing the way it worked. And for the record, the old connections were not RS-232 ports, so the question is a bit off the mark. Yes, they had some RS-232 components, but they weren't full-featured.
If memory serves, IBM invented this cable format for the PS/2. (You do remember IBM had a computer called the PS/2, right?) This particular connector might have been adapted from something else (strong resemblance to a Mac kbd/mouse connector, as I recall), but the big public play was with the PS/2. It was smaller, cheaper, etc, than the AT keyboard connector, and therefore a win all around. IBM then quickly adapted it for use with their `standard' PCs, and everybody followed. (Again, this was back in the days when IBM did something and everybody followed.) It was (and is) signal-compatible with the old keyboard, and I've still got a few of those ATPS2 keyboard adapters around somewhere in the dungeon.
At the time the AT-style keyboard connector was put on PCs (early 1980s), nobody ever dreamed we'd be having roomfuls of these things all cabled up to a single monitor/keyboard/mouse. The computers were too expensive for a person to own more than one, and not powerful or reliable enough to put into racks and stacks to provide specialized services. The kind of switching talked about here just wasn't envisioned, and in fact, would have been considered insane. Putting more expense into the component so it could be hot-swapped (and making the appropriate O/S changes) was simply not worth doing.
But eventually technology catches up, and the marriage of USB with keyboard/mouse permits the right thing to happen. One could argue that you ought to simply be able to plug/unplug the keyboard from USB host to USB host, and in fact, you can do that with some of them. But that still doesn't solve your monitor connection problems, and last time I checked, SVGA didn't work over USB. So a single switch that moves 3 components simultaneously is a big win.
I looked over the article posted at the top, and am pretty impressed. USB KVM switches are a great idea, and after reading over the above articles, I want one. In fact, I want both of 'em, because each has some very cool features.
Hmmm... so I guess I'll wait until the next generation comes out, when each company adds features from the other. :-)
I'm using the reviewed Belkin KVM with a Samsung SyncMaster 900NF fed from a Geforce2 at 1600x1200 at 75hz. I'm using an integrated video+USB cable made by Belkin, and have no perceivable degradation whatsoever. I used to have slight ghosting with cheap cables, but now there's none at all.
If you're a picky graphics designer-type, then you may "see" artifacts that noone else in the world can pick up, but the setup is beautiful for regular people.
Dewey, what part of this looks like authorities should be involved?
The SOHO OmniView USB/Audio switches USB keyboards and mice between computers without having to reinstall them after each switch, but the same can't be said for USB peripherals. Each time you select a new PC, the OS detects new USB peripherals.
I don't think that this point was made enough by the reviewer. I bought a 4 port KVM (forget which maker), but it took USB mouse and keyboard inputs, instead of PS/2. Basicly the fact that the computer needs to install the devices again is THE MOST ANNOYING THING IN THE WORLD. After I discovered this little problem, I returned the product and got a ps/2 input one. In the review, the first product doesn't have to install the mouse and keyboard, but I would imagine for the USB devices, it would be the same annoyance. If you have a KVM, you want to be able to switch from one computer to the next instantly. Here you cannot, I just don't think the reviewer spent enough time with it to really see how annoying this fact is.
This is nonsense. When sales people tell you that an item they sell does not work well, you can believe it. When several people from different companies tell you the same thing, you can believe it.
I have a Playstation 2 ( with the linux dev kit) and a Debian box in the same room, that I want to share with a KVM ( USB would be ideal but I'll take PS/2 if needed). The thing is I was told that KVM's do not work with Sync-on-Green monitors ( which the Playstation 2 needs). Is this totally true and if so are there Sync-on-Green converters?
The Rose technology matrix switch to serve 1, 2 to 4 users is a quite good switch.
....
Blackbox also distributes them as "their own" switch.
If you are in need with a new switch you should look to these because the switch has up to 40m support without quality loss of the image; can use a line extender up to 300m and has a exclusive feature to protect your ports by groups and users.
For example user A can access all servers while user B can only look to server 1 and 2, user C can control server 1, 3 and look to server 8 but not control it,
It also has OSD and is expandable to more of these units.
The more-expensive unit (rack expandable) is expandable in any way.
Look at the pdf for more info.
The 2 users * x ports (pdf)
The 4 users * x ports (pdf)
The high-end series. (info)
--- I am known for the ones who want to find me on the net. Is that a privacy risk or a privilege? One might wonder..
For instance, I'll switch from the PC to the Mac, and the PC won't notice that its USB peripherals have disconnected. Switch back to the PC and all those peripherals don't work. Nothing solves the problem but rebooting the PC.
Also, if I leave Netscape 4.7 running on the Mac and switch over to the PC, half the time when I switch back to the Mac, Netscape crashes, often killing the Mac in the process. It's weird, but it's happened often enough that I now shut down Netscape before switching.
Far more often, the USB mouse (Logitech optical cordless) will simply freeze on the PC in mid-use. Unplugging/replugging its USB cable fixes the problem. I don't know whether to blame the IOGear switcher, the mouse, WinXP, or USB. I'll probably start using 2 mice instead.
If you only switch occasionally, this might be ok. If you frequently switch (as between RISC workstation and PC), it's unacceptable.
4% of USB KVMs are actually just simple mechanical switches. They have all the same problems as above, plus, striclty speaking, they violate USB rules, and can have nastly malfunctions if they don't have correct precedence for power-on/off (as USB connectors do).
1% of USB switches, just now entering the market, have "spoofing", aka "sniffing", aka emulation of devices. A correctly implemented spoofing switch never lets any host see a disconnect. Designing this is far from trivial. USB is complex, and the varieties of keyboards and mice are effectively infinite if you're trying to chase them all for purposes of emulation.
In addition to the IOgear mentioned above, there is only one other spoofing switch that I'm aware of, and it isn't fully debugged yet.
In the meantime, I recommend:
Wait for this USB KVM situation to get sorted out. And it will need to soon, as PS/2 ports will be vanishing from new machines next year (and already have from many 64-bit platforms).
you dont ;)
UNLESS something at that distance supports USB, then use a USB CDROM
with M$ Natural Keyboard. M$ Intellimouse III works 100% though. Here's what IOGear said:
USB devices, specifically mice and keyboards, are each given a VID number (Vendor Identification) upon release. This VID# is read by your computers' OS's and the device installed; however, since many mouse and keyboard manufacturers hold the rights to the VID# of their product, we cannot "emulate" or "copy" it without their written concent.
At the release of our MiniView II KVM, we anticipated this to be resolved shortly; however, that has not been the case in our dealings with many mouse and keyboard manufacturers. Currently, we are only able to "emulate" a standard, full-size USB keyboard; however, keyboard shortcut keys (E-Mail, Internet, Eject, Volume, etc.) are not guaranteed to function. We hope to support these features in the future in both our current and future line of USB KVM products. The same holds true with mice. Since we are only able to emulate the standard, Microsoft-compatible Intellimouse (Two Button with Wheel), any extra features on mice are not guaranteed to function..
In the meantime, we apologize for any inconvenience, and hope that you'll find the excellent features and technological advances of your MiniView KVM offset the possible loss of mouse and/or keyboard functionality.
Let me know if you have any further questions, or if I can be of further assistance.
A red delicious apple is better than a kvm switch and shouldn't cost more than $1.50.
I tried the Belkin product reviewed in the article and I took it back to the store after about 20 minutes. I've also tried a couple of their older models.
I don't know how Belkin works on other monitors, but I have a top of the line Sony 21" monitor, which has a very crisp display. When I attach a Belkin to the system, I get 7 or 8 prominent ghost lines flowing off the right hand side of all the windows on the screen. The picture quality is horrible.
After returning the Belkin I tried a Linksys KVM and a Cybex. The Linksys was nice, but still had some faint ghost images (nothing as pronounced as the Belkin and it is a lot cheaper) but the Cybex KVM is great (albiet more expensive). No ghost images whatsoever.
Overall, I think the Belkin KVM is the worst KVM I've ever used. I hope other people have better luck with it that I did.
I use it as well but I have two problems with it.
1. The cables are too short so the box is way in the back that I had to reach for the switch button on the box every time I need to switch. This actually compounds the second problem.
2. There is no keyboard hotkey switch, which makes it a hassle to remove my hand from the keyboard and go reach behind my monitor to switch. (See problem 1)
Other than these, it works alright.
I am using a USB KVM. It works great where Windows boxes are concerned, but not so well with Linux or FreeBSD. The problem is, as far as I can tell, that Linux and FreeBSD both support USB but get confused when the keyboard and mouse disappear and then reappear (actually Linux can deal with the keyboard, but not the mouse). Consequently, my USB KVM was utterly useless when I connected my Windows box and my FreeBSD server, and I needed a second mouse in order to share the Windows box and the Linux box.
From this behavior I gather that these two OSes support USB devices, but not Plug and Play. Or maybe I'm wrong, the manufacturer was no help...
Anyway, has anyone else had this problem with USB KVMs + Linux or BSD?
I started out with punch-cards on the HP-2000 in the mid-1970s... Yes, I remember! ;-)
At the time the AT-style keyboard connector was put on PCs (early 1980s), nobody ever dreamed we'd be having roomfuls of these things all cabled up to a single monitor/keyboard/mouse.
But the AT-style ("old" style) keyboard ports were hot-swappable.
(Again, this was back in the days when IBM did something and everybody followed.)
No. The PS/2 came out in the late-1980s if memory serves. But the industry standard remained "old style" keyboard plugs up until just a few years ago... say 96~97. By that time, IBM was just another player in the commoditized PC industry.
No, the industry-wide switch did NOT happen just because IBM came out with the PS/2. It happened a decade later. I bought my last "old-style" motherboard in 1998, which was just about the time when they were starting to get scarce (well, here in Taiwan anyway). (And I bought it specifically because I already had a KVM switch for the old-style keyboard (w/ serial mouse) and had a couple of machines still in service that didn't even have PS/2 ports.
The kind of switching talked about here just wasn't envisioned, and in fact, would have been considered insane.
Hmm... no, when the changeover actually occurred (late 1990s) this kind of switching was already commonplace. And the price of any serial device had already dropped more-or-less to commodity levels. (Hell, by that time we didn't even have to ask whether or not it had a 16550A chip!)
Actually, the most sensible explanation I've heard so far is that RS-232 is half-duplex and PS/2 is full-duplex. But I don't even know if this factoid is accurate... let alone why it would make a significant difference with stuff like kbds and mice...
But eventually technology catches up, and the marriage of USB with keyboard/mouse permits the right thing to happen.
Yes, I'm planning to buy a USB kbd and KVM soon. I need to upgrade my systems anyway, now that the new Debian is out... just busy with other shit lately...
Frankly, by the time this "sea-change" occurred, there was plenty of reason to anticipate losing the connection to any given input device, and yet nobody ever thought to upgrade the PS/2 protocol to make it hot-swappable. That's what always made me wonder what those motherboard designers were smoking... ;-)
Anyway, what's done is done. Just gotta deal with it... I'm just curious about the motivation behind it. And I still don't have a satisfactory answer... :-/
--jrd
PS: Here's some info on PS/2 ports that might be of interest to folks who know more about electronics that I do...
XML is like violence. If it doesn't solve your problem, you're not using enough of it. --AC
Why? WHY?!
It's terribly outdated. Try Mozilla (or Chimera.)
Or use IE 5. Eesh.
...and I don't have any problems at all with my 4-port Belkin OmniCube and my Microsoft PS/2 mouse unless I perform a switch between boxes during POST time (when rebooting the box), in which case the mouse is sometimes not detected by that box.
The OSes currently installed and working with the four PC's connected to the KVM are as follows:
* PC-DOS 6.3
* OpenDOS 7.01
* Mandrake Linux 8.1
* Mandrake Linux 8.2
* Red Hat Linux 7.3
* OS/2 Warp 4 (FixPak 15)
* eComStation 1.0
* Windows 95 OSR2
* Windows NT 4 (SP6)
* BeOS 5 Pro
* FreeBSD 3.5
* Solaris/x86 7
The only OS which has given me problems other than at POST time is eComStation, which for some reason wants to be in the foreground for the entire boot process or the mouse doesn't get properly detected.
In *all* other cases, I have seen no problems.
Note: my hardware is all from the 1996-1997 time period, including the mouse, so it's possible that newer hardware is more problematic.
Mainframe/UNIX Bit Twiddler and long time Windows/Linux Hobbyist.
The Theorem Theorem: If If, Then Then.
I have keyboard, monitors, and mice that I can swap for the KVM cables if for some reason I want to have someone use one of the KVM'd boxes concurrently.
If I really need to display things on two boxes concurrently by myself, I use either X or VNC (depending on the platform(s) involved).
Mainframe/UNIX Bit Twiddler and long time Windows/Linux Hobbyist.
The Theorem Theorem: If If, Then Then.
Some of us DEPEND on KVM switches, and to us it's a topic of critical importance.
/. only appeal to a subset of the user base. IF you don't want to read something, just move on to the next topic...
Most topics on
Mainframe/UNIX Bit Twiddler and long time Windows/Linux Hobbyist.
The Theorem Theorem: If If, Then Then.
We have had all three.
Some older Belkin boxes we cursed at for lack of MS Intellimouse support, but I don't think that is an issue anymore.
We now have an Omniview PS/2 4port that looks much the same as the one in the article. It works pretty good, though we have only tried it on PC's.
We bought a two-port IOGear USB switch for a Mac and SunBlade workstation. The SunBlade would not recognize any USB keyboard we tried through the KVM switch. Therefore I would not recommend it to anyone for use with Sun's.
We also got an 8-port USB switch from NTI (http://www.networktechinc.com/), which we use on our projection system. We like it a lot. We split the video output using a Startech video splitter and pipe the SVGA output to the switch box and the other side to the monitor. We connect the USB directly to the KVM switch from the computer. Then the output from the KVM switch goes to the projector and a wireless keyboard and mouse. We got the NTI KVM that works with an onscreen display so that it was easy for our users to come in and know which line was connected to which computer. The workstations keyboard and mouse, and display still works as usual. When selected, the projector would display what was on the computer's monitor and the wireless keyboard and mouse could be used to remotely manipulate it.
I can recommend the NTI KVM switch. At the time we bought it, it was the only 8-port pure USB switch on the market. It seems very compatible with a wide variety of computers including Sun, Mac, and PC (all under USB). We are having a few problems with the keyboard and mouse, probably because they are wireless. We sometimes have to cycle power on the KVM switch to get the mouse and keyboard back. That and sometimes the KVM switch seems to turn on NumLock CapsLock and ScrollLock on the keyboard. We use an Interlink wireless keyboard which has the keypad integrated into the main part of the keyboard, accessed from a function key (much like many laptop keyboards do). This is baddddddddd, since the NumLock being on messes up half the keyboard. We plan on buying a Gyration keyboard and mouse and hope to have better luck with it (but we will see).
See my Re:Belkin Caveats for the solution to the lost scroll mouse on Linux.
Signatures are a waste of bandwi (buffering...)
DVI does have a different connector to VGA.
-James