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The Coming of Serial ATA
GrendelT writes "Tom's Hardware has a review of the newest Serial ATA gadgets that are soon to hit the market. With speeds of 150Mb/s, thinner and longer cables, backwards compatibilty with Parallel ATA (what most of us have right now), and the option of being hot-pluggable, it seems the next step in storage technology is upon us."
That's what I originally thought, too. But the story title is a typo: They're talking about 150MegaBytes/sec, not bits.
The next version of firewire on the horizon will only be able to do 100Megabytes/sec (800Megabits/sec).
Still, I'd much rather they dump Serial ATA altogether and concentrate on FireWire. 100Megabytes/sec is just plenty, and FireWire is a much more general and flexible standard.
But a very important design point in serial ATA is that it is completely backwards compatible with parallel ATA. No software need change. This is not the case if we were to drop *ATA in favor of firewire. Now you can upgrade at your leasure, and mix and match (convertors exist to plug your old drives onto a serialATA cable).
Don't know if you know this or not, but Serial ATA is 150MB/s... as in, 150 megabytes per sec.
The speed of this product really isn't the selling point, at least not now. Most 7200 ATA drives can't sustain much more than 40MB/s, let alone 150MB/s. The current ATA 133 is already overkill. The selling points are the small cable, the decreased voltage (signal voltage decreased from 5v to 150mv), the length increase, the future posibilities, and the adoption of much more popular serial design (similar to firewire and usb).
Err, yeah... I managed to get my Athlon XP installed and attached the heat-sink without crushing the core, but man was I unprepared for the hell that involved plugging in those IDE cables!
Damnit! Those basdards are always forcing us to upgrade! Change one part and you need a whole new motherboard! I have all these extra ISA alots and I can't use them? OK, so now I'm just being silly...
Firewire is a physical transport layer for SCSI[*] which has been around for a very long time. The rub is simply the lack of drives with a native firewire interface. Everything I've ever seen contains a IDE/1394 bridge.
Firewire is a more generalized interface -- storage, video, communications, etc. Where Serial ATA is (at the moment) 100% focused on storage. This is where the current bloody ATA mess comes from (IDE was engineered for hard drives and then people started plugging other crap on the chain.)
* Technically, ATA is a physical transport for SCSI too. It's just in a red-headed, bastard, step-child fashion.
Look at those benchmarks. If they can match a Parallel ATA drive with only 8 wires, imagine what they could do if they used as many as the parallel ATA drive.
Just say no to round ATA133 cables. Every other wire on an 80-wire IDE cable is a ground. It's there to shield the data wires from one another.
When you bunch the individual wires up like that, you destroy the shielding. At high data transfer speed, you are going to get CRC errors due to interference, and this means lower performance as the IDE controller has to deal with them.
Rounded cables are suitable for low speed applications like CDROM and floppy drives.