Slashdot Mirror
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.
From the pictures in the linked article, the two connectors look pretty similar. Is there anything to make it easy to tell which is which when you're crawling around on the floor under a desk trying to plug something in? And are they idiot-proofed at all? A client of mine one managed to force a 6 pin firewire cable in the wrong way around (tough, but possible, as he proved) and blew the bridge circuit in the external drive case. This looks like it might be even easier to mess up... or will it be like the Sony power supplies with a 'really easy to spot' 0.5mm blip on one side of the tiny black plastic connector?!
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?
Am I the only one who is nonplussed with the rapidity of basic interface changes among components? It would be a shame to see SATA take the path of AGP or CPU sockets, where the interface seems to be in a constant state of flux even though the hardware which USES the interface never actually improves at a matching pace.
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.
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
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?