The decreased access times
gained from disabling AAM on the Barracuda ATA IV bring it a negligible increase in the Business Disk WinMark 99... 0.7% to be exact. Gains in the High-End Disk WinMark 99 are a bit more significant, though at less than 3% still not a difference one would likely notice.
In contrast, the difference in WinMarks turned in by quadrupling buffer size is immense. The WD1000BB-SE exhibits a 25% improvement over the BB in the Business test! This gain builds upon a drive that was already the ATA category leader in this measure. Put into perspective, the BB-SE's score of 10.9 MB/sec trails only Seagate's 15,000 RPM Cheetah X15-36LP... by a scant 2% margin at that!
Though improvements aren't quite as breathtaking, they're nonetheless significant in the High-End test. Here the BB-SE builds on the standard WD1000BB (again already the ATA leader here) with a 13% gain, landing itself in the midst of today's top SCSI drives.