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SubjectRe: Pentium memcpy patch. Unintended effect?
On Fri, 7 Feb 1997 aidas@ixsrs4.ix.netcom.com wrote:

>
> I patched and compiled 2.1.25 with the Pentium memcpy patch. Everything
> works fine, except for Quake. Now, Quake runs a fair bit choppier.
>
> I'm not really concerned about Quake. I'm more concerned whether this is
> some kind of defect in my hardware, or simply a side effect of the design
> of Quake. The latter seems more likely.
>
> The system is a P133, 32MB EDO RAM, Premio motherboard (model unknown),
> XFree86 3.2.

Okay. Before I say anything stupid, let me just say that I really know
next to nothing about Pentium optimizations.

That said, I do know that Quake is very floating-point intensive, and the
pentium-memcpy patch uses the FPU to perform 64-bit-wide memory copies. I
would guess that this would put more demand on the FPU and cause the Quake
slowdown.

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