I have the current drivers and BIOS for the SCSI RAID card...
I dunno what else it could be.
It seems that all my drives are slow. Here is the benchmark from my 4 drive RAID 5 SCSI 160
HD Tune: MEGARAID LD 0 MEGARAID Benchmark
Transfer Rate Minimum : 42.0 MB/sec
Transfer Rate Maximum : 48.7 MB/sec
Transfer Rate Average : 46.0 MB/sec
Access Time : 8.0 ms
Burst Rate : 50.3 MB/sec
CPU Usage : 2.8%