One other point that I should have mentioned (this is (as usual) better suited to SCSI than IDE, but...) The cache lets you aggregate all of the data during a disconnect. You can store the requested data and not worry about sync xfers. IDE doesn't do disconnect, but chances are, you'll collect before you ack, so you can burst out the xfer at the best available speed.
I get several 120V AC shocks each year (and a number of 60VAC (120Hz) shocks, too)... of course, the number has gone down quite a bit, and most of them only run through one hand (or foot - now that feels really funny), so it's not quite so dangerous... if you get current running through your trunk or head... that's another story.
In one finger and out the other causes some cool muscle spasms, though. One downside of electrical shock is that it can tense your muscles, strenthening your grip on the item that is shocking you, causing better contact... etc... don't grab lines with your palm...
I've only once suustained a burn, and that was about 3-5 seconds of contact (seems like forever, though...)
True, the device driver and fs cache *should* have that stuff in it, but it isn't always that way. Plus, you can often tweak the read-ahead for the on-drive caches...
I was trying to give a simple answer to a simple question - guess it was a little oversimplified...
The drive's cache can be read-ahead or a write cache (usually some combination). You request these 64 bytes of data (say, some config info for a vehicle in a game), it reads in that, and some more, so when you come back and ask for the next data sequentially, it'll be there. It's usually slightly more sophisticated than this, but you get the idea...
Writes can post to the cache, and then the bus can go on it's merry way. Much faster (though long bursts will eat this up really quickly).
SCSI devices usually let you enable/disable whether to cache writes - there's probably an ATA command for it, but I don't happen to know how to do that off hand.
>There can be two HDD on this bus, don't just think about one HDD.
but IDe can only deal with one at a time - you always have to wait for seeks... SCSI supports disconnect (I'm sounding like a broken record here). Thus, you performance is hampered.
Transfer rates go up, but 4 disks in a stripe set will always give you much better r/w performance (or two in a mirror for reads)... too bad IDE can't support that properly - two devices per channel? 7/15 sounds a lot better than 2/4
It's worth going to U2(or U3) SCSI for the cable length, then - more flexibility/expandability, better performace, the better drives first...
This is another attempt to extend a dying architecture... let it die peacefully...
Yup - the SCSI bus protocol has disconnect - give me this data (I'll go talk to somebody else while you're looking). IDE doesn't - give me this data (hurry up, will ya... I'm tired of waiting for so long). 5-20ms of time best served elsewhere (if you have more than one drive).
I've had far more IDE controllers fail than SCSI controllers across all the machines I've worked on (taking percentages into account), but there's nothing quite like a RAID controller dying... makes you want to tear your heart out...
Hey man - my C64 had a 1540 floppy drive... yeah! And the 128 has a *really fast* 1572 drive built right in. It was like heaven. Now I didn't even have to switch program and data disks - whoo-hoo!
GO SCSI - better protocol, better interface, better drives (especially CD drives).
SCSI has disconnect, while ATA just hangs around waiting... kinda kills your multi-disk throughput. Of course, it was never designed to support more than one drive at a time (effectively a drive and a CD) for each channel...
Well, Asus made a number of boards with adaptec chips built on (a nice deal), and there were other boards offered with the tekram equivalents. The Asus P2B-S, DS, LS (S - SCSI, D - Dual CPU, L - 10/100 lan onboard). There were other versions (in the P3 line) and other board manufacturers who offered this. (as I remmeber, Macs were SCSI for a long time, and only recently have degraded to IDE for cost reasons).
My main system: Adaptec 2940UW (haven't upgraded past that yet) IBM 9GB UW 10krpm drive (had it since they first came out... gotta love those seek times and xfer rates) IBM 18GB UW 7200 RPM ('just' for storage - still ~15-20 MB/s sustained xfer) IBM 4GB UW 7200 (this one was old, and a little slow, but still nice) Plextor UltraPlex Wide (40x UW SCSI) Plextor PlexWriter (8/2/20) 100 MB Zip SCSI 1 GB Jaz SCSI
1 interrupt (shared with another card) 1 DMA
CD copying takes up next to no CPU usage, and I can thrash gigs of files between drives or across the LAN without noticing a performance hit...
One of the other systems is running a newer 14GB 7200 UDA/66 drive. Fast, but still nothing compared to the 10krpm drive (few are). The system also gets more bogged down with CD activity...
SCSI - Set a couple jumpers, add devices to your heart's content... IDE... 2 per cable ?! It's been a long time, but backward compatability keeps some things around far too long...
hmmm... my sarcasm must have gotten a little carried away there 8^) It tends to do that from time to time if I don't keep it well fed. Better put it down for the night - no telling what it might do later.
Yep - let the idiots burn their brains out with the drug of choice, but add a law (this is my favorite part) that allows any drug-related crime (say shoplifting while high on crack so one could buy more) to warrant the death penalty. Self overdose or something kind (like skinning). Enough cocaine to kill a horse. Then they die happy and get the heck out of the gene pool.
Meanwhile, the tax income from sales would be nice...
(in a perfect world, this might work......... of course, in a perfect world, we wouldn't have 10yr old addicts, either)
>BTW: Internet: Built on Unix. Innovative? Make your own decision, but what has changed the world of computing recently?
I'd claim that some of the routing protocols in use today are the most innovative part of the Internet. Fair Queuing, Multicast, QoS, etc. all sound fairly obvious, but somebody had to have the original idea (just like OOG and the wheel).
>I must contest "the wheel hasn't changed much in the last several thousand years either" >... anyone else wanna try?
Um... we now have all sorts of wheels. Still mostly round, though. Tires have been a great add-on innovation for the wheel, though that really goes back to the native tribe who dipped their feet in latex before they went hunting, for protection. So tires are just round shoes, and nothing innovative. Hmm... What about those neat carbon-fiber light wheels. Much lighter and less inertia than those old stone ones. A heck of a lot better for the tour de france...
I seem to get a lot from non-existent domains, as well as the usual fake usernames... my favorites are the ones that have all sorts of formatted text and some sort of scripted link that would probably take me to a page... if I were using Outlook...
I even click on them now and then - the script sends me to something like http:/000000000000000000000000/[crap here too] not very useful in pine, Eudora, etc., but I'll bet it works great in Outlook...
I can see the argument getting him out of court, but as for the boiling oil...
I'd just run a stand nearby... "Get your boiling oil heeeeere! Hot oil! Hot oil!" and - "Can't tell the spammer without a program! Free program with your purchase of any 300 degree or hotter oil!"
...being a recent RPI Computer & Systems Engineering grad ('99), and watching the IT major go through birthing pains, I can tell you that nobody will become a productive software developer because of that program. Rather, they could become a productive (anything) despite that program. The program is evolving (I hope) past the state in which it started... The curriculum looked to be straight out of the management school, with almost *no* CS or Eng classes. Some, but not nearly enough. Data Structures should still be a required course for something along this line. I found the initial curriculum severly lacking in technical content. IT shouldn't be a management degree with CS1 and a JAVA course, it should be more of an applied CS/CSE track...
IT Revolution Myth or Reality - 2 hours twice a week?!?! Time better spent elsewhere. This could be two or three two hour sessions per semester - more of a school colloquia. Not a four credit course...
All the people I knew who were switching into the major were people who decided that engineering or CS was too tough for them, and they'd rather do management, but this seemed like an easier was to get a job (I still haven't figured out undergraduate management programs, but that's another story).
If you can't pass a basic circuit class or Computer Science 2 in your sophomore year (many freshmen take it their first semester), I don't want you in an IT curriculum. Ever. This shouldn't be management, it should be more of what you described. Unfortunately, it isn't.
Some of the best programmers I've seen have been engineers who learned to program from necessity - through the same classes at the same time as the CS majors, but they seemed to get a lot more out of it. The feeling of applying programming to practical use is more solved in software engineering than it is in that IT major...
Slashdot Mirror
One other point that I should have mentioned (this is (as usual) better suited to SCSI than IDE, but...) The cache lets you aggregate all of the data during a disconnect. You can store the requested data and not worry about sync xfers. IDE doesn't do disconnect, but chances are, you'll collect before you ack, so you can burst out the xfer at the best available speed.
I get several 120V AC shocks each year (and a number of 60VAC (120Hz) shocks, too)... of course, the number has gone down quite a bit, and most of them only run through one hand (or foot - now that feels really funny), so it's not quite so dangerous... if you get current running through your trunk or head... that's another story.
In one finger and out the other causes some cool muscle spasms, though. One downside of electrical shock is that it can tense your muscles, strenthening your grip on the item that is shocking you, causing better contact... etc... don't grab lines with your palm...
I've only once suustained a burn, and that was about 3-5 seconds of contact (seems like forever, though...)
True, the device driver and fs cache *should* have that stuff in it, but it isn't always that way. Plus, you can often tweak the read-ahead for the on-drive caches...
I was trying to give a simple answer to a simple question - guess it was a little oversimplified...
The drive's cache can be read-ahead or a write cache (usually some combination). You request these 64 bytes of data (say, some config info for a vehicle in a game), it reads in that, and some more, so when you come back and ask for the next data sequentially, it'll be there. It's usually slightly more sophisticated than this, but you get the idea...
Writes can post to the cache, and then the bus can go on it's merry way. Much faster (though long bursts will eat this up really quickly).
SCSI devices usually let you enable/disable whether to cache writes - there's probably an ATA command for it, but I don't happen to know how to do that off hand.
>There can be two HDD on this bus, don't just think about one HDD.
but IDe can only deal with one at a time - you always have to wait for seeks... SCSI supports disconnect (I'm sounding like a broken record here). Thus, you performance is hampered.
Transfer rates go up, but 4 disks in a stripe set will always give you much better r/w performance (or two in a mirror for reads)... too bad IDE can't support that properly - two devices per channel? 7/15 sounds a lot better than 2/4
It's worth going to U2(or U3) SCSI for the cable length, then - more flexibility/expandability, better performace, the better drives first...
This is another attempt to extend a dying architecture... let it die peacefully...
SCSI is cleaner
Dirty as the name may sound
Kicks major ass too
hey, it *could* be a Dihatsu...
Yup - the SCSI bus protocol has disconnect - give me this data (I'll go talk to somebody else while you're looking). IDE doesn't - give me this data (hurry up, will ya... I'm tired of waiting for so long). 5-20ms of time best served elsewhere (if you have more than one drive).
I've had far more IDE controllers fail than SCSI controllers across all the machines I've worked on (taking percentages into account), but there's nothing quite like a RAID controller dying... makes you want to tear your heart out...
Hey man - my C64 had a 1540 floppy drive... yeah!
And the 128 has a *really fast* 1572 drive built right in. It was like heaven. Now I didn't even have to switch program and data disks - whoo-hoo!
GO SCSI - better protocol, better interface, better drives (especially CD drives).
SCSI has disconnect, while ATA just hangs around waiting... kinda kills your multi-disk throughput. Of course, it was never designed to support more than one drive at a time (effectively a drive and a CD) for each channel...
Well, Asus made a number of boards with adaptec chips built on (a nice deal), and there were other boards offered with the tekram equivalents. The Asus P2B-S, DS, LS (S - SCSI, D - Dual CPU, L - 10/100 lan onboard). There were other versions (in the P3 line) and other board manufacturers who offered this. (as I remmeber, Macs were SCSI for a long time, and only recently have degraded to IDE for cost reasons).
My main system:
Adaptec 2940UW (haven't upgraded past that yet)
IBM 9GB UW 10krpm drive (had it since they first came out... gotta love those seek times and xfer rates)
IBM 18GB UW 7200 RPM ('just' for storage - still ~15-20 MB/s sustained xfer)
IBM 4GB UW 7200 (this one was old, and a little slow, but still nice)
Plextor UltraPlex Wide (40x UW SCSI)
Plextor PlexWriter (8/2/20)
100 MB Zip SCSI
1 GB Jaz SCSI
1 interrupt (shared with another card)
1 DMA
CD copying takes up next to no CPU usage, and I can thrash gigs of files between drives or across the LAN without noticing a performance hit...
One of the other systems is running a newer 14GB 7200 UDA/66 drive. Fast, but still nothing compared to the 10krpm drive (few are). The system also gets more bogged down with CD activity...
SCSI - Set a couple jumpers, add devices to your heart's content... IDE... 2 per cable ?! It's been a long time, but backward compatability keeps some things around far too long...
hmmm... my sarcasm must have gotten a little carried away there 8^) It tends to do that from time to time if I don't keep it well fed. Better put it down for the night - no telling what it might do later.
Yep - let the idiots burn their brains out with the drug of choice, but add a law (this is my favorite part) that allows any drug-related crime (say shoplifting while high on crack so one could buy more) to warrant the death penalty. Self overdose or something kind (like skinning). Enough cocaine to kill a horse. Then they die happy and get the heck out of the gene pool.
Meanwhile, the tax income from sales would be nice...
(in a perfect world, this might work......... of course, in a perfect world, we wouldn't have 10yr old addicts, either)
Most of the time those remove addresses aren't valid, either... that's what really gets me going...
I usually forward all of those to spamrecycle@ChooseYourMail.com
www.spamrecycle.com
Cut their fingers off... that's an appropriate punishment... and cut the fingers off with their own bronzed and sharpened tongue...
Muhahahaha!
no - not organized. It makes it prevalent, common, frequent... but not necessarily organized...
>BTW: Internet: Built on Unix. Innovative? Make your own decision, but what has changed the world of computing recently?
I'd claim that some of the routing protocols in use today are the most innovative part of the Internet. Fair Queuing, Multicast, QoS, etc. all sound fairly obvious, but somebody had to have the original idea (just like OOG and the wheel).
>>...I didn't realize Rob Pike smoked crack.
>Is this some post generation X thing? We Gen-X'ers don't get it....
Um... which Gen-X are you claiming to be a part of? This is late 80's -> mid-late 90's terminology.
From Oxford: Crack - 9 sl. a potent hard crystalline form of cocaine broken into small pieces and inhaled or smoked for its stimulating effect.
>MS's contribution was the case,
oooh.... shiny 8^)
>I must contest "the wheel hasn't changed much in the last several thousand years either" ... anyone else wanna try?
>
Um... we now have all sorts of wheels. Still mostly round, though. Tires have been a great add-on innovation for the wheel, though that really goes back to the native tribe who dipped their feet in latex before they went hunting, for protection. So tires are just round shoes, and nothing innovative. Hmm... What about those neat carbon-fiber light wheels. Much lighter and less inertia than those old stone ones. A heck of a lot better for the tour de france...
Hmmm... wheels...
no..... it would be Treet...
and if that doesn't make you sick...
I seem to get a lot from non-existent domains, as well as the usual fake usernames... my favorites are the ones that have all sorts of formatted text and some sort of scripted link that would probably take me to a page... if I were using Outlook...
I even click on them now and then - the script sends me to something like http:/000000000000000000000000/[crap here too]
not very useful in pine, Eudora, etc., but I'll bet it works great in Outlook...
I can see the argument getting him out of court, but as for the boiling oil...
I'd just run a stand nearby...
"Get your boiling oil heeeeere! Hot oil! Hot oil!"
and -
"Can't tell the spammer without a program! Free program with your purchase of any 300 degree or hotter oil!"
>Of course there is. Bob.
Twitch, twitch... [retch]
...being a recent RPI Computer & Systems Engineering grad ('99), and watching the IT major go through birthing pains, I can tell you that nobody will become a productive software developer because of that program. Rather, they could become a productive (anything) despite that program. The program is evolving (I hope) past the state in which it started... The curriculum looked to be straight out of the management school, with almost *no* CS or Eng classes. Some, but not nearly enough. Data Structures should still be a required course for something along this line. I found the initial curriculum severly lacking in technical content. IT shouldn't be a management degree with CS1 and a JAVA course, it should be more of an applied CS/CSE track...
IT Revolution Myth or Reality - 2 hours twice a week?!?! Time better spent elsewhere. This could be two or three two hour sessions per semester - more of a school colloquia. Not a four credit course...
All the people I knew who were switching into the major were people who decided that engineering or CS was too tough for them, and they'd rather do management, but this seemed like an easier was to get a job (I still haven't figured out undergraduate management programs, but that's another story).
If you can't pass a basic circuit class or Computer Science 2 in your sophomore year (many freshmen take it their first semester), I don't want you in an IT curriculum. Ever. This shouldn't be management, it should be more of what you described. Unfortunately, it isn't.
Some of the best programmers I've seen have been engineers who learned to program from necessity - through the same classes at the same time as the CS majors, but they seemed to get a lot more out of it. The feeling of applying programming to practical use is more solved in software engineering than it is in that IT major...
Just my $.05