Subject: Re: Intel Atlantis motherboard cache woes
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Michael L. VanLoon -- HeadCandy.com <michaelv@HeadCandy.com>
List: port-i386
Date: 06/22/1996 15:37:46
>On Sat, 22 Jun 1996 14:01:42 -0700 
> "Michael L. VanLoon -- HeadCandy.com" <michaelv@HeadCandy.com> wrote:
> > Assuming the problem isn't the CPU, you might also try a memory bus
> > speed of 60MHz, instead of the ~66MHz you're using with both 166MHz
> > (~66.7 * 2.5) and 133MHz (~66.7 * 2).  This is in case your RAM just
> > can't keep up.  Try running at 150MHz (60 * 2.5) or 120MHz (60 * 2).

>I assume there's some way to change this via the BIOS or a jumper on the 
>mainboard?  Need to install a new crystal?

With any decent motherboard this should probably just be a jumper you
change.  You should have a jumper for the bus speed and the
multiplier.

> > On my ASUS P55TP4N, the motherboard L2 cache is write-through, and the
> > Pentium's on-chip L1 cache is write-back.  I would expect this to be
> > the typical arrangement since the Pentium is designed with an internal
> > L1 write-back cache, and having two write-back caches makes the
> > coherency logic much more complicated.

>Ah, ok.  So, all of it should be dealt with in hardware...software 
>shouldn't have to touch it?

Correct.  But this still doesn't mean you should assume the Intel
motherboard caching is infallible.  Remember, they have screwed it up
in the past (early versions of 486 PCI chipsets).

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  Michael L. VanLoon                                 michaelv@HeadCandy.com
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