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eSATA Connectors
buffalocheese writes "Since the introduction of the Serial ATA 1.0a specification in 2002, many manufacturers have introduced PCI and CardBus cards with both internal and external SATA connections.
At first these internal and external connectors were completely identical, but later, external connectors started to appear which were still fully compatible with the internal sockets but featured added extra screening for external use.
With the introduction of the SATA II specification in mid 2004 a new external SATA connector was defined. These new external (eSATA) connectors are not compatible with the original internal SATA connection.
Currently there are add-on cards and drive housings available which feature both types of SATA connection for external use. Gradually the older types will disappear and all new SATA cards will feature the eSATA connector for external drive connections."
Frankly, I'm not a big fan of the current SATA connectors. They tend to fall off at the slightest provocation. I can't work in my case without having to check at the end that all of the SATA connectors are still in place (and at least one of them is usually loose or completely off). Because of this I've been reluctant to switch to SATA on external enclosures. If this new connector can prove itself resistant to falling off, it may in fact be a winner (I would even advocate unifying the connectors again under the new standard). I do like the fact that both the external and internal SATA connectors are currently the same, I just don't like the connector itself. It's rather nice to be able to take an old AT power supply (the kind where the power switch is hardwired to the supply) and plug in an off of the shelf SATA drive to the back of my case in a pinch. Plus, fewer connector types means fewer adapters I'll eventually have to own.
I read the internet for the articles.
I really don't see the advantage in having 2 types of connectors doing the same thing for internal and external use.
Except they want to sell me another cable - or did I miss anything?
While I'm not as certain when it comes to graphics cards, PCI-Express is/was sorely needed to replace PCI for general expansion cards. PCI had a limited amount of bandwidth available that was extremely easy to saturate (A single gigabit NIC would hit a bandwidth wall at something like 400mbit). The shared nature of the PCI bus was also an extremely frustrating limitation.
By contrast, PCI-Express 1x slightly increases the bandwidth from roughly 133MB/s to 150MB/s, but more importantly each device gets that, it's not shared anymore. And of course, 2x and higher slots provide more bandwidth.
But when it comes to graphics, AGP 8x was (at the time) providing more than enough bandwidth... as for the demands of modern monsterous graphics cards (such as the 8800 GTX), for all I know they might be able to saturate an AGP 8x bus.
As I understand it anyhow, the more tangible benefits from moving from AGP to PCI-Express were increase bi-directional bandwidth (AGP was great at Host->Card, but sucked at Card->Host), and increased ease with sticking multiple PCI-Express slots on the motherboard, making modern SLI possible.
Oh four pin molex;
With your twin ground connections;
You're so down to earth.
I don't know about you, but while IDE and SATA may not have a noticeable performance impact, it sure is nice to have SATA when building or upgrading a computer. First SATA connectors are smaller, so they don't block airflow like ribbons. And second, SATA bypasses the insane primary/secondary, master/slave, legacy support, jumper hell.
As far as your AGP and ddr2 gripe. AGP had reached the limit of it's functions, and PCI-express is a better standard than AGP ever was. And DDR2 is not anything to whine about, DDR1 still exists and is compatible in most motherboards that support DDR2. In fact, if anything, DDR1 has gotten cheaper as a result. The only problem is they can't work mixed.
One other thing I wonder about. I thought that Intel also switched to PCI-express, DDR2, and SATA. Perhaps I was mistaken and Intel is a backwards company and use slower technology with their faster processors. Bear in mind that only applies to Intel motherboards, since it's the chipset that determines compatibility with most of that stuff. So blame VIA, or nVidia, and not AMD. For reference, my Gigabyte mobo has SATA and IDE connections, and supports DDR1 and DDR2 (though with AMD that is from the processor).
/end AMD fan ranting/
Yes it's an anecdote! Were you expecting original research in a Slashdot comment?
I felt like I was in the classroom listening to the instructor drone on as I read this article summary. While this may be worthwhile to know, it's unexciting to the point of boring. The slownewsday tagger was correct.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
AGP was only fast one way pci-e is fast for bandwidth both ways.
With your fit so tight
My bloody knuckles curse you
Die molex die die
That's standard, most SATA cables lack any sort of locking clip which makes them fantastically unsafe to use. My suggestion is to not move your desktop a lot. And if you do move it, check the cables first.
:-)
In my case I spent an hour or so chasing cables that would pull out, e.g. secure it to the mobo, it would pull on the drive. It didn't help that I had 4 SATA drives at the time...
If you're so inclined you could try gluing them into the mobo, then tape it to the drive. Bonus points for using duct tape, the true Canadian solution
Tom
Someday, I'll have a real sig.
One correction, one addition:
I'm fairly positive that it's 250 MB/sec per lane, not 150 for PCI-E.
In addition, not only is that per-device, it is per-device, per-direction (full duplex, 250MB/sec to the device and 250MB/sec back at the same time)
As to why PCI-E couldn't have been developed back when PCI or AGP were available (rather than incremental steps) - Moore's law. It simply wasn't possible to make silicon capable of handling PCI Express data rates (each lane uses serial communications at 2.5 gbits/sec, which was definately NOT possible with the silicon available back when PCI or AGP were initially developed.)
For those that wonder why PCI-E uses 2.5 Gbit/sec signaling but only transfers 250MB/sec of data, it is because all data is encoded using either 4B5B or 8B10B encoding (I can't remember which of the two), which maps every 4 data bits to 5 signal bits for 4B5B or 8-to-10 for 8B10B. This is done to ensure a minimum number of bit transitions in a given period of time, and also ensure that the signaling has no DC bias. (i.e. equal number of 0s and 1s no matter what the input data is).
retrorocket.o not found, launch anyway?
Ethernet over one single hop (no switching) has a latency of under 1ms. Over two cables with a switch in the middle, and adding on the overhead of IP, I get a round trip time of 0.2-0.3ms. The average seek time for a hard drive is 4-9ms. The extra latency of using ethernet would not be significant.
A lot of latency can be added by expensive protocols like SMB or NFS, but something like iSCSI can be very fast.
I am TheRaven on Soylent News
SATA II is the old name of the organisation that created the SATA standard (although I can't find what the acronym used to stand for). It has since changed its name to SATA-IO ("International Organisation") because everyone mistook the two I's as Roman numerals and assumed the newly created SATA 3Gb/s standard was "version 2" of SATA. It's not. It's just a new signalling rate and other features like NCQ are separate.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
I'd rather see drives with native FireWire controllers than SATA or eSATA. Sure, SATA gives more bandwidth, but only in theory. A single hard drive comes nowhere near close to being able to saturate a FireWire 800 link, let alone [e]SATA. On the other hand, you can plug multiple devices into a FireWire chain. I have two FireWire 800 hard disks on a shelf, and I can connect them to my laptop with a single FireWire cable. If I moved to eSATA then my laptop would need two eSATA ports, and I would need to plug in two cables. This doesn't exactly seem like a step forward.
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Ignore the other responder to your question. Your cables suck. There's better ones available. I used to do embedded software development on a system that used 4 (or 8 or 16) SATA drives, and I've gone through a lot of different cables. Some don't attach very securely, and sound like the ones you have. Others were very secure; I could pick up the drive and move it around in operation and the connector didn't come loose. I believe some of the better cables had "Foxconn" connectors. We also found that newer cables seem to be better than the 1st-generation SATA cables.
In summary, try some different cables.
It's not a bad idea, save the configuration part. How does the drive get an IP address? How does it resolve conflicts for addresses with other devices on the bus? How does your motherboard find the attached devices? If you're running iSCSI it's not just an Ethernet connector, it's a full-on TCP network. There are solutions to these problems, but they go beyond "add an Ethernet interface" -- you'd need DHCP and SLP or the likes at the very least just to get everything talking, and all embedded both on the disk and in the pre-boot environment.
You could drop iSCSI and just use layer-2 Ethernet to transfer blocks, but then you'd have to define a comm protocol for disks on layer-2 Ethernet. Not that it couldn't be done, but I'm not aware of one in common use today (at least not on commodity Ethernet hardware). I think this sort of solution is more feasible, as it's closer to the standard motherboard bus technologies, but there would have to be some motivation to develop the comm protocol and write drivers for it for both the OS and the pre-boot environment.
What's wrong with IEEE 1394 as a generic system interconnect? It has global addressing, it's hostless, it's hot-swappable, supports a large number (compared to the needs of the average desktop for example) of systems per bus, it works over reasonably long cable runs (very long if you use Cat-5 or optical connections) -- it's a lot like Ethernet in all those respects. And it's already got wide support for block access, DV streams, TCP/IP and a variety of other transports. Why do you want to invent a new block access protocol for Ethernet?
Only catch is if I hook up a drive while in Windows with that converter, it'll lockup. Has to be turned on before I boot the computer. This is a limitation of the adapter; from what I've read, you should be able to hot swap with a "real" eSATA port.
Another possible reason for your inability to hot-swap is that the SATA ports might be set to "IDE mode" in the motherboard's BIOS. This is a common setup on "home-built" computers since "IDE mode" allows pre-Vista Windows installation without the "F6 (floppy) installation method." To enable hot-swap, the SATA ports must be set to "SATA/AHCI mode" in the BIOS.
Here's some instructions from Intel's site on changing SATA modes on their motherboards:
- IDE mode - no AHCI, no RAID
- SATA mode (sometimes called AHCI mode) - AHCI enabled, no RAID
- RAID mode - AHCI enabled, RAID enabled
AHCI mode also allows for Hot Swapping drives.TO START
PRESS ANY KEY
Where's the 'ANY' key? I see Esk, Kitarl, and Pig-Up...