Unusually low performance (Drive C)

I visited WWW.PCPITSTOP.COM , ran the test and got very good results except for "• Unusually low performance (Drive C)

Drive C has an uncached speed of 1.45 megabytes per second.

For comparison, systems with the same CPU, clock speed, and memory size as this one have an average uncached speed of 3.95 MB/s ".
This is a new Seagate 20 Gig that is defragmented every day.
pc pitstop said virus scan may be causing the problem so I disabled it and had the same results.
Anyone out there know what to do on this?

 

I know nothing of PitStop; but, there are 7200-RPM drives and 5400-RPM drives. There are also drives that have lots of on-disk cache (2 Megs) and others that have far less. There is ATA-66 and ATA-100. The ATA-100 drives perform better with an 80-conductor cable.

I don't know if this helps; but, I thought I would just drop it in the pot, anyway.

 

In device manager check in the properties of the drive to see if DMA is enabled. If not, enable it and then run the test again.

 

I think it's an ATA 100 but I don't think it's 7400 rpm. (It's just one I found on special somewhere). I enabled the DMA but didn't fix the problem although it tells me I'm a little faster today.......
Drive C has an uncached speed of 2 megabytes per second.