Subject: Re: Advice wanted from Sun users please (fwd)
To: None <current-users@NetBSD.ORG>
From: Jeff Thieleke <>
List: current-users
Date: 03/30/1996 01:57:16
> > 	There is a reason that he may succeed where you failed.  The
> > motorola chip have much, much higher tolerances for this type of
> > hackery.  If you're lucky and have a big heatsink, you can find
> > motorola chips that can be overclocked 50% or more.  With intel chips,
> > I've rarely heard of clock increases of more that 10-15% being
> > successful.
> > 
> Don't overclock a 68030. 

Don't overclock any CPU, unless you think the benefits will outweigh the
potential chance of chip damage/malfunction.  But there is nothing unique 
about overclocking a '030, though.

> When the 25MHz 68030 chips came out on accelerator cards for the Amiga,
> some companies wanted to come out with a 28Mhz version. Just to be
> 3mhz faster, you know. This looks neat on paper.

I am almost certain you meant the 68040.  I know GVP had an overclocked 
28MHz 040 accelerator, but I don't remember any overclocked 030 cards.

> The problem is, if you overclock that chip by the 3mhz, the math starts
> to go. You get strange low level math errors.

This definitely isn't true.  I had a 40MHz 030 overclocked at 50MHz for 
over a year, with no problems.  However my 40MHz 68882 FPU was flaky at 
anything above around 45MHz, so maybe you are thinking of this instead.

Jeff Thieleke