Foxconn Renaissance BIOS has badly distributed MTRR

[renordw]

I am just requesting a better suited MTRR distribution mapping for 64 bit architecture.

The 8 MTRRs are spread out in such a way that they work with x86 architecture which is less than 3383MB. But, they really are not optimal for the amount of memory they can support which is up to 24GB, plus some GPU RAM in the PCI-e slots.

One of the consequences is that if you put in a GPU with a large amount of memory relative to the total RAM, it mismatches the e820 and MTRR mapping, causing windows of uncacheable memory to float to the top and totally wreck the system's performance.

The only solution I've come up with so far is truncating the memory in Windows 7 to the exact amount of RAM sticks, (6GB) in my case. So, the PC doesn't get the advantage of the RAM in the GPU.

I would like to modify the BIOS to redistribute the MTRR mapping such that it is optimized for 64 bit operating systems, even if it is not ideal (or useable) for 32 bit.

[renordw]

Actually it turns out that the system works better if I truncate it to around 3.3GB, which is a huge waste. I have 6GB of RAM, but the BIOS does not distribute it properly.