First post, by jasa1063
- Rank
- Oldbie
I recently got a 386/40 computer with a Biostar motherboard containing a MACRONIX MX83C305FC/MX83C306FC chipset. I am using Micro-Labs ET4000AX video card, Sound Blaster 16 CT4170 sound card, and a GoldStar Prime 2c multi IO card. I have Compact Flash to IDE adapter with a 2GB Compact Flash card running DOS 6.22. The AMI BIOS has options to change the divider for the AT Bus clock from 2-5. Here are the results of a few benchmarks:
AT bus clock divider 5 (8Mhz)
3Dbench 1.0 - 14.4 FPS
Coretest 3.03 - 2.2 MBs
AT bus clock divider 4 (10Mhz)
3Dbench 1.0 - 15.6 FPS
Coretest 3.03 - 2.4 MBs
AT bus clock divider 3 (13.3Mhz)
3Dbench 1.0 - 15.6 FPS
Coretest 3.03 - 2.9 MBs
AT bus clock divider 2 (20Mhz)
3Dbench 1.0 - 16.0 FPS
Coretest 3.03 - 3.3 MBs
At 20Mhz my Sound Blaster 16 does not work at all, so the highest stable clock I can get is at 13.3Mhz. As you can see there is a point of diminishing returns with the video card beyond 10Mhz. The disk performance does continue to scale up. I decided to run the AT bus at 10Mhz as I feel that is a pretty safe overclock to run for an extended period of time. I am curious what others have experienced overclocking the AT bus on their 386 or 486 system.