i have a seagate scsi hard drive(ST3146707LC),wanna use it on my pc which has only pci and pci-e slot.i wanna buy an adaptec scsi card ,160MB/s or 320MB/s ? is 320MB/s scsi card much faster than 160MB on pc?

Well the drive has a SCSI 320 Interface so would presume one would adhere to the spec.

http://www.ultratec.co.uk/TechSecti...

http://en.wikipedia.org/wiki/SCSI

I have tried both adaptecs 160 and 320 and have not noticed that much difference in speed and if your harddrive is a 160 then you won't notice any speed difference at all due to the limitation of the harddrive.

Hard drives do not run at their max rated speed all the time.

160 and 320mb/sec is the max BURST data transfer speed (so is e.g. 133mb/sec for IDE drives, and 150 or 300mb/sec for SATA drives). It can only be used for short periods of time - how long depends directly on the size of the ram cache (buffer) built into the drive - if the drive continues to be accessed, the ram cache is no longer used and the drive reverts to it's much slower sustained data transfer rate - e.g. fastest I've seen is 55mb/sec on recent drives. When you are transfering large files, most of the time the drive is running at the slower sustained rate. A drive runs no faster than the sustained data transfer rate much of the time.

Whatever the SCSI controller is capable of, it can't run the SCSI drive any faster than the max burst speed the drive is capable of.

SCSI drives are often nearly identical to IDE drives made by the same maker - the only difference is it has an additional SCSI related chip and a SCSI connector instead of an IDE one. SCSI specs in theory are much better than those for IDE drives, but in the real world there isn't much performance difference between a SCSI drive and a nearly identical IDE drive model made at the same time by the same maker.
If you can find a suitable used SCSI card for a cheap price, that's a viable option.
BUT if you have to buy a NEW SCSI card to use this drive on your computer, that's not cost effective. SATA drives perform better in real life, and your mboard probably supports SATA-2 drives, capable of 300mb/sec burst speeds. A new SATA-2 drive may cost you less than a new SCSI card.

Unless you have a pci-x you can't really use the U320. The backplane is too slow on the normal pci.

I read it wrong and answer it wrong too. So get off my case you peanut.

Though pci slot is slow,but my pc has pci-e slot and Adaptec 29320LPE support pci-e.Is 29320LPE on pci-e slot much faster than a 160M card on pci?

Be careful, your scsi hd is an 80pin unit, not a 68pin like the host card ribbons. You'll still have to buy an 80pin to 68pin adapter board with a 4pin power supply connector. By the time you buy a host card, scsi LVD ribbon, 68pin adapter , LVD terminator; you could buy three sata drives!

NT-W2K-XP-Borg-SCSI

I think it would be faster.

The only real way is to use performance tests. Some devices and drivers act very differently than what one would expect.

I read it wrong and answer it wrong too. So get off my case you peanut.