I got ahold of 2 new WD6401AALS HDs. This is the 640GB version of Western Digital's Caviar Black series.
Both are manufactured on September 13, 2008 and they seem to post identical results. The benchmarks were done with HD Tune 2.55.
I've thrown in benchmarks for the 500GB Western Digital Caviar Blue (WD5000AAKS) and also the 300GB Western Digital VelociRaptor (WD3000GLFS).
In two words...the WD6401 is the fastest 7200rpm hard drive I've ever played with - it delivers VelociRaptor-like transfer speeds at 33% of the cost. AWESOME HDs!
WD6401AALS HD 01:
WD6401AALS HD 02:
WD3000GLFS:
WD5000AAKS:
Transferring large files from one WD6401 to the other WD6401 gets an average transfer rate of 95MB/s according to Vista's dialogs. If I transfer small files the average is anywhere between 50 and 65MB/s.
If I transfer files between my VelociRaptor WD3000GLFS and one of the WD6401 drives, then my average is about 105MB/s.