First post, by dj_pirtu
Figured out yesterday that VT8228 clock chip can do 66MHz FSB so tried and it worked.
CPU is late i486DX4/100 WB Enhanced and takes 2x66MHz=133MHz with no problems. (Tried 3x50MHz=150MHz on that QDI V4S471 but didn't make it to DOS)
Cache needs to be slowed down a little and CPU to PCI Post Write needs to be disabled or strange things will happen. If enabled and when in heavy CPU load, screen stops updating and DOS4GW gives some kind of real mode -error. When disabled it just kills PCI-speed (display card, Cirrus 5446 PCI) from 40MB/s -> 20MB/s.
My other system QDI V4S471 with CX5x86 (2x50MHz) is just as fast in memory operations, it's cache timings are fastest and memory 'faster'.
But still, that i486DX4/133 is quite fast.
Anybody else have tried 66MHz clock on this mobo?