I just installed my Adaptec AHA-2940UW card and connected a 4gig SCSI HD. Now, I looked up the model of the drive, they are made by Fujustu, the M2954 is the model. These are supposed to be 7,200rpm with 36 MB/s buffer throughput. Now why in the hell am I getting a maximum read and write speed of 4,000kb/sec on this 7200rpm SCSI drive when my ATA66 5,400rpm IDE drive gets read/write speeds up to 21,000kb/sec???

have you enabled DMA?
just a thought

Umm, this is a SCSI drive I'm talking about here. Just exactly how do you enable DMA on a SCSI drive in WinXP?

I looked up details on your drive and card and yes, you should be getting a lot better performance than you say you are.

Things to consider:

File Sizes - it will be slower reading lots of small files than one big file

Fragmentation - fairly obvious


but apart from these things there is not much I can suggest other than check support site for adaptec and fujitsu for setup and performance tips.


BTW - you were right, you cannot set DMA for a SCSI drive.