[ On Wed, May 20, 1998 at 00:25:04 (+0900), Izumi Tsutsui wrote: ]
> Subject: Re: Overclocking
>
> In <199805190715.DAA01543@cs201.wmich.edu>
> naamato@cs.wmich.edu wrote:
> 
> > I just threw a 48Mhz oscillator at U110 (replacing the 40 MHz
> > one) on my 3/60.  I'm seeing some very strange behavior.  
> 
> > a)  Has anyone been successful with this procedure?
> 
> I used 3/60 with 50MHz oscillator few years ago.
> It almost worked fine, but sometimes dumped cores
> with signal 4 and 11 in summer. ;-)
> I think faster SIMMs(~80ns), faster CPU/FPUs (25MHz?)
> and cooling chassis fans are recommended.

I have a 3/60C in slot 12 of my 3/260 rack-mount machine that's running
with a 50MHz crystal.  It ran SunOS with X11 and tkined/scotty for many
months, and ran NetBSD under test for some time too.  I didn't upgrade
the SIMMs or anything else.  I was going to replace the CPU, but it
seems unnecesary.  All I did was clamp a small cooling tower on with a
thin strip of spring steel and with that heat transfer grease
underneath.  Mind you the rack also has two 10" fans in the roof blowing
directly down through the 3/260 chassis (the chassis was missing the fan
tray when I got it), so it's never very warm, even in the heat of summer
(it's in the basement, but the basement gets hot in the summer with that
monster blowing out heat).

The extra 5MHz makes a big difference to the speed of X11 on the colour
framebuffer.  It's almost fast enough again to be useful!  ;-)

-- 
							Greg A. Woods

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