Info: Windows XP 64 Bit New Install (same thing happens in Windows XP). Segate 320Gig Sata II. De-fragmented many times. Is happening on two different HD (but same Model).

Fresh install Windows XP 64Bit + software (3 Gig on HD). Create temp directory, and keep copying a 120MB .mp3 file a few times. It is extremely fast (almost instant). At around 30Gig, slows down. At 40 Gig takes about 5 seconds to copy paste. Delete the temp files (back to 3 Gig HD usage). Repeat with same results (fast at first but as HD reaches 30 gig usage, starts to slow down). Tried many different combinations (different locations, empty directory etc.), but in the end, at 30 to 40 Gigs, HD apparent access time slows way down.

Why is this happening? Should I have one 25 Gig partition for Windows + software and the rest for data?

If you have a dir with 10.000 files it is normal... Your benchmark method is not valid.

I would agree but we aren't talking 10,000 files per directory: only around 20 in the directory. I had also tried, before even posting, to copy to an empty directory. Still the same issue. Less then 30 Gig on HD, really fast. More then 30 Gig, and copying to that empty directory takes a lot longer (4 or 5 seconds instead of "instant.").

This isn't really a benchmark test as much as a usability issue. I really think there is an underlying issue here with SATA, Windows XP and/or the Segate model drives I bought (I have three of them).

I am just wondering if anyone else has noticed this issue?

On damaged drives, yes. In some case it was the FW, in other was a HW problem.

Thank you BlackST for your time. You've seen this happen on damaged drives... Not good for me then because the 2 drives I bought (same model at different times over 6 months from different sources) are both exhibiting the same behavior: even in different machines. So, maybe I have been unlucky here and got two bad drives.

Thanks for your time. I'll go buy a different drive by a different manufacturer and see what happens.