While not a strictly SATA RAID, the Raptors/SeriTek appear to be the glue that really makes this RAID fly.

4x X15.3 on UL4D, 100MHz slot.
4x Raptor74 on SeriTek/1VE4, 100MHz slot.
4x Atlas 15K II on UL4D, 133MHz slot.
Striped all 12 drives, 8 channels, with SR 3.2.1, 128KB SU.

QB 2.1 report:
QuickBenchÈ 2.1 Test Results File
©2000-2005 Intech Software Corp.
Test file created on Thursday, October 20, 2005 at 10:25:23 AM
Test Volume name: 12xSCSIsataSCSIsr

Extended Test Size: 100 MB Read: 689.803 MB/sec Write: 762.125 MB/sec

Post to the DB under SATA, 9th entry down. k