PDA

View Full Version : ATA vs SCSI


buzzfgo
Oct 8, 2004, 01:25 PM
I just found out that my G4 has a SCSI card in it. Would I see any gains in speed with a SCSI hard drive vs an ATA one?

tomf87
Oct 8, 2004, 01:30 PM
Even though SCSI is a more efficient bus, you most likely won't notice any performance gains with one or two drives. You may actually lose performance if the SCSI card is really old (SCSI-1 or SCSI-2).

edesignuk
Oct 8, 2004, 01:45 PM
Depends if you can put a 15k U320 SCSI drive on it :D

tomf87
Oct 8, 2004, 01:51 PM
Depends if you can put a 15k U320 SCSI drive on it :D

Still one drive won't be that much faster at transferring data. Even though the spindle speed is faster, the MB/sec doesn't increase that much with one drive. To get higher performance you need to use multiple spindles together.

Then if you connect it to a SCSI-1 or SCSI-2 card, you are operating at those slower speeds.

bousozoku
Oct 8, 2004, 02:16 PM
Still one drive won't be that much faster at transferring data. Even though the spindle speed is faster, the MB/sec doesn't increase that much with one drive. To get higher performance you need to use multiple spindles together.

Then if you connect it to a SCSI-1 or SCSI-2 card, you are operating at those slower speeds.

Well, since so much of an ATA drive's speed depends on the main processor, a slower machine may benefit from even an UltraSCSI card, since it doesn't require the main processor to be involved as much.

tomf87
Oct 8, 2004, 03:16 PM
Well, since so much of an ATA drive's speed depends on the main processor, a slower machine may benefit from even an UltraSCSI card, since it doesn't require the main processor to be involved as much.

Not sure what you mean there. The controllers for IDE/ATA drives are built on the devices. There really is no controller on the mainboard. That's why they are termed host bus adapters.

Anyway, the SCSI card will plug into a PCI slot anyway, which is CPU controlled, so you're still hitting the CPU with something.