The cards don't offer any performance benefits right now, simply because there are no SATA drives available. Changing the interface does do alot; but it does next to nil when only one side is changed. Meaning exactly what I said before, there is not going to be any performance benefit when using a Parallel ATA drive with a Serial ATA controller.
But when comparing the Serial ATA interface to Parallel ATA, Serial ATA outweighs PATA in tons (IMO.. the tons part).
- Max burstable transfer rate
- Parallel - 133MB/s theoretical (currently.. anything faster is economical suicide for mass market. ie. SCSI)
- Serial - 150MB/s theoretical, only the first iteration of Serial ATA (further iterations could allow up to 600MB/s bandwidth).
- Power requirements
- Parallel - 5V transceivers (1 per wire), which prevents higher bandwidth without adding technology like LVD (Low Voltage Differential signaling) - which basically raises the prices to those around SCSI's
- Serial - 500mV max, peak to peak
- Pin count
- Parallel - 80 wires per cable (26 per channel + power/ground), effectively 5cm wide
- Serial - 7 wires per cable (1 channel), effectively 8mm wide
And I felt this one was somewhat important as well... even though I'm not going to put it in the bullet form like above:
Because each cable for Serial ATA is only a single channel 'solution', it
currently requires 1 controller (chip) per channel. On the other hand, Parallel ATA, in its current elderly state (around 20 yrs old) only requires 1 controller for up to 2 channels, under E/IDE standards.
There's also the cable length issue, current in servers, and possibly full-tower cases:
Current Parallel ATA requirements can only allow cables up to 18 inches in length, per channel.
Serial ATA's requirements are a lot more lenient: it allows the cable to be up to 1 meter (approx. 3 feet) in length, per channel.
IMHO, Serial ATA is much more than just a cable improvement over Parallel ATA..
But until Serial ATA hard drives start showing up on the market (no more than 2 months from now), all Serial ATA is going to be is a smaller cable...
And don't worry.. I know I didn't get everything. Those are just the most important features at this time, and imo, again. Now all we need is a better HDD technology (preferably something like flash RAM), and a better I/O bus (PCI Express, formerly 3GIO).
-Tarmax
Edit for readability and some other stuff