Re: AMD Write allocate option info

Juhani Rautiainen (
Thu, 11 Dec 1997 15:39:16 +0200 (EET)

On Wed, 10 Dec 1997, Patrick St. Jean wrote:

> Ok, here's the info from 21326c.pdf (Implementation of Write Allocate in
> the K86(tm) Processors)
> --- begin fair use extract ---
> Write allocate in the AMD-K5(tm) processor is supported only on Models
> 1, 2, and 3, with a Stepping of 4 or greater. Write allocate in the
> AMD-K6(tm) MMX(tm) enhanced processor is supported only on Models with a
> Stepping of 1 or greater.
> --- end fair use extract ---
> I'm going to bang out a patch for this this weekend. That's about the
> only time I'll have to get my system up to snuff with respect to glibc and
> stuff... Look for something on or about Saturday evening...

I thought that this should be handled by BIOS. This was one of the reasons
why early K6 benchmarks showed slower results. Atleast Asus T2P4 has BIOS
update which enables write allocation. I think that also most of the other
boards that support K6 processors in BIOS do this automatically. Maybe
some older boards with processor adapters could use this though.

> Pat


Juhani Rautiainen