Re: Pentium memcpy patch. Unintended effect?

Derrik Pates (dpates@Cavern.NMSU.Edu)
Fri, 7 Feb 1997 08:08:17 -0700 (MST)

On Fri, 7 Feb 1997 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.

This is because the 3-D object modeling scheme used in Quake makes HEAVY
use of the FPU. When you're doing large memcpy()s and such, it starts
competing for access to the FPU. This is where your problem is at. If you
can live with the extra bit of choppiness, go for it. I'm still on 2.0.27,
and last I played Quake (Pentium 90, 16 MB RAM, S3 868 vid card w/2 MB
RAM), it was not noticable to me, and I do use the Pentium memcpy patch on
my box.

Derrik Pates

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