Re: Inconsistent fixed MTRR settings in BP6
Jamie Lokier (lkd@tantalophile.demon.co.uk)
Tue, 30 Nov 1999 13:43:22 +0100
Erich Boleyn wrote:
> This means that the BIOS didn't set up the MTRRs (Memory Type Range
> Registers) in the same way for both CPUs.
>
> This is actually allowed in the MP BIOS definition. But it's kind of a
> rotten trick to play on someone if their OS doesn't know how to take
> care of it, as it usually ends up just making your system run pretty
> slow, but otherwise functionally correct.
Some combinations of different cacheability settings on x86 CPUs are
documented to deadlock the CPUs. Seems quite serious to me.
-- Jamie
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