I have a question about hard drives

[Artas1984]

I have two hard drives: drive A and drive B.

When i copy Z stuff from drive A to drive B, i get transfer rate of lets say 100x.
When i copy Z stuff from drive B to drive A, i get transfer rate of approx 20x.

Question: which of the hard drives is the bad one? The Z stuff is identical.

This might sound stupid, but i thought that simplicity works best.

Both drives are similar btw, 7200 rpm, 32 Mb, sata interface.

[insanemonkey]

Try running a program like hdtune on each drive to find out which one is causing the problem.

[tinymouse2]

+1 for HDTune.

Benchmark both drives and error check them. That should tell you which one (if one of them) is the bad drive.

Also it could just be that one of the drives is designed to have a very fast read rate but a fairly slow write rate. Oh and is one of the drives a boot drive?

[Xaotic]

Are the two drives in identical conditions, i.e. used space, defragged etc. Fragmentation and available space will play into the performance. If drive A has limited space and is fragmented, then it will be significantly slower, though a factor of 5 would likely indicate other issues.

Similar drives can also have completely different geometry and areal density resulting in other factors that can affect performance.

Could you provide specifics on the two drives?