tod wrote:

I just bought a Seagate 300GB ATA drive with 8mb of cache, $70 ($120- $50
rebate =$70)
The store also had the 16mb cache version for $20 more.
Thinking of going back to exchange for the 16mb version.
What is the performance difference?

You wouldnt be able to pick it in a randomised double blind trial.

The bigger cache is worth it if its free, but thats about it.