I think they're used to let the chipset know how exactly to handle stuff like caching on the CPU that's installed.

Doornkaat wrote on 2020-08-10, 21:17:

I think they're used to let the chipset know how exactly to handle stuff like caching on the CPU that's installed.

Like Write-Back versus Write-Through?

Yep, WB vs WT, what A20 is doing, multiplier and voltage settings.

It's incredibly frustrating how almost no manuals actually tell you what is going on, even when they have settings for (at the time of writing) not yet available CPUs that turned out to require different settings when actually released. So you need to reverse-engineer it all. Doable if all parts are known-good, but if you don't know for sure motherboard and/or CPU works that can be incredibly frustrating...

The whole statement is based off something I think I read in a motherboard manual once. I don't remember it being any more specific than stating that the jumpers are related to caching, sorry.

dionb wrote on 2020-08-10, 21:34:

Yep, WB vs WT, what A20 is doing, multiplier and voltage settings.

It's incredibly frustrating how almost no manuals actually tell you what is going on, even when they have settings for (at the time of writing) not yet available CPUs that turned out to require different settings when actually released. So you need to reverse-engineer it all. Doable if all parts are known-good, but if you don't know for sure motherboard and/or CPU works that can be incredibly frustrating...

Yes quite frustrating. It’s interesting to see zero performance gain in Dos Quake between two cpu jumper selections but up to 10fps difference in GLQuake.