I had some time to investigate the possibility of undocumented fsb settings
Ths clock gen is a ICS 9148af-58
I wasn’t able to find a data sheet for it
So I tried all (literally all) the combinations and came up with this using a low multiplier on the cpu, external cache disabled and loose memory timings.
I believe the 225 setting is 112mhz fsb a undocumented setting!
I have now set the multiplier to 5.5x and fsb to 112mhz giving me 616 mhz cpu
But it appears that the motherboard cache doesn’t like running this fast even at fast timing (as apposed to fastest)
Trying 3.4v I/O
Trying 3.5v I/O
Trying 3.6v I/O
No go, went to a black screen instead of usual hang though.
It seems that 112mhz is the only undocumented setting and you have to give up cache in order to use it.
The tests will continue without cache!
Gave 6x multi a try, that’s a no go. It posts to something about boot block.
Not surprising as that’s probably 670mhz. Bummer that it didn’t work, we can all dream though. Maybe I can try it at higher voltage though. This is at 2/2.1v now.
I actually got it into memtest at that speed but not for long and rebooting it didn’t want to post again. Back to 5.5x 2.2v and let’s see what we get.
No cache, normal ram timings, 616mhz core clock and aquamark is doing a run!
So far this speed seems stable. The only question is wether or not it’s faster given that I had to give up 2mb of 4ns cache to get here…
616 core 112fsb seems stable because I made it through aquamark with loose memory timings.
Aquamark score dropped of course, 6,500
Now to tighten memory timings and see if we can get a score increase!
Okay, so I tightened timings to turbo for all three, and 2 and did another aquamark.
It’s really missing that cache.
All that for nothing..
Back to 100x6 🤣 and cache!!!