PCMark04	Source: FutureMark

PCMark04 is an application-based benchmark and a premium tool for measuring overall PC performance. It uses portions of real applications instead of including whole applications or using specifically created code. This allows PCMark04 to maintain a smaller installation size while still giving accurate results.

PCMark04
XP Startup:	MB/s	Ranking
Western Digital Raptor WD740 HDD	11.384
Western Digital Caviar SE16 WD4000KD HDD	9.453
Western Digital RaptorX WD1500AHFD HDD	12.096
Western Digital RaptorX WD1500AHFD (w/o NCQ)	11.825
Application Loading:	MB/s	Ranking
Western Digital Raptor WD740 HDD	10.382
Western Digital Caviar SE16 WD4000KD HDD	8.98
Western Digital RaptorX WD1500AHFD HDD	11.025
Western Digital RaptorX WD1500AHFD (w/o NCQ)	10.984
File Copying:	MB/s	Ranking
Western Digital Raptor WD740 HDD	50.767
Western Digital Caviar SE16 WD4000KD HDD	51.416
Western Digital RaptorX WD1500AHFD HDD	61.156
Western Digital RaptorX WD1500AHFD (w/o NCQ)	61.131
General HDD Usage:	MB/s	Ranking
Western Digital Raptor WD740 HDD	8.882
Western Digital Caviar SE16 WD4000KD HDD	7.916
Western Digital RaptorX WD1500AHFD HDD	9.557
Western Digital RaptorX WD1500AHFD (w/o NCQ)	9.827

Here with PCMark04 we see that the Western Digital RaptorX WD1500AHFD HDD keeps up with the higher RPM Raptor WD740 very well!

PCMark05	Source: FutureMark

PCMark05 is a premium tool for measuring both normal home use and simple 3D performance of the latest PC hardware. There are 11 system tests - each one is designed to represent a certain type of PC usage. By running these tests, PCMark05 stresses the components in a similar manner as they are stressed in normal home usage.

PCMark05:
XP Startup:	MB/s	Ranking
Western Digital Raptor WD740 HDD	11.42
Western Digital Caviar SE16 WD4000KD HDD	9.451
Western Digital RaptorX WD1500AHFD HDD	11.970
Western Digital RaptorX WD1500AHFD (w/o NCQ)	12.063
Application Loading:	MB/s	Ranking
Western Digital Raptor WD740 HDD	10.47
Western Digital Caviar SE16 WD4000KD HDD	9.01
Western Digital RaptorX WD1500AHFD HDD	11.092
Western Digital RaptorX WD1500AHFD (w/o NCQ)	11.210
General HDD Usage:	MB/s	Ranking
Western Digital Raptor WD740 HDD	8.885
Western Digital Caviar SE16 WD4000KD HDD	7.887
Western Digital RaptorX WD1500AHFD HDD	9.657
Western Digital RaptorX WD1500AHFD (w/o NCQ)	9.618
Virus Scan:	MB/s	Ranking
Western Digital Raptor WD740 HDD	89.359
Western Digital Caviar SE16 WD4000KD HDD	91.702
Western Digital RaptorX WD1500AHFD HDD	95.115
Western Digital RaptorX WD1500AHFD (w/o NCQ)	95.277
File Write:	MB/s	Ranking
Western Digital Raptor WD740 HDD	70.27
Western Digital Caviar SE16 WD4000KD HDD	62.12
Western Digital RaptorX WD1500AHFD HDD	85.350
Western Digital RaptorX WD1500AHFD (w/o NCQ)	85.504

Looks like the 16MB of onboard cache makes a big difference. The Western Digital RaptorX WD1500AHFD is even able to outperform the Raptor in the Virus scan portion of PCMark05!