Need high MB/sec I/O using AMD and 100MHz drive

I am currently using an AMD K6-2 333/IDE system for database application development and I am ready to upgrade to improve the disk I/O. A few days ago I purchased an Athlon 900MHz system using a DFI motherboard. After installing Win98 and running “Performance Test V3.3” I discovered the disk I/O was only 5MB/sec. My 333 system was at 3MB/sec! The new system also included a WD 7200 RPM 100MHz 30 gig HD. The DFI only supported 66MHz disk I/O and the HD was set properly. “Performance Test V3.3” has a 1 gig Athlon w/ Asus MB showing disk I/O of 23 MB/sec.

Before purchasing another system I would appreciate hearing what others are using for high performance disk I/O (IDE based). I would minimally require 100MHz disk I/O and would consider spending a bit more for RAID (I don’t require it now but may utilize it in the future if available.). As for MB/sec I would like to minimally be over 20.

As for the processor I am looking for an inexpensive alternative so I’m going with AMD. BTW an recommendations for a case/cooling fan as quite as a DELL system?

TIA,

Qnerd