[SunRescue] Sparc Overclocking....

[Peter Koch]

Hi!

>I'd like to try overclocking this system...

My overall experiences with overclocking Sun computers wasn't
very successful! At most you can gain 10% from the server machines
and 10-25% from desktop machines. The highlight in my overclocking
scores got the Sun 3/60 which all could be overclocked 20 or 25%.
Others like the 3/50 or 3/75 became flaky when overclocked more
then 10%.

Here is a table:
	3/50: replaced 60 MHz by 66 MHz (15 to 16.6 MHz) and had
		failures after some hours
	3/60: replaced 40 MHz by 45,48,50,55,60 MHz (20 to 22.5,24,25,
		27.5,30 MHz) and machines ran stable with 24 or 25 MHz
		and failed after some hours/minutes with 27.5/30 MHz
	3/75: replaced 33.3 MHz by 38 and 40 MHz (16.6 to 18,20 MHz)
		and the machine ran with 18 MHz but didn't even come
		up with 20 MHz
	3/260: replaced 50 MHz by 55,60 MHz (25 to 27.5,30 MHz) and
		the machine ran, but hung at reboot with 30 MHz.
	3/470: replaced 66.6 MHz by 70,72,80 MHz (33.3 to 35,36,40 MHz)
		and the machine ran with 36 MHz but didn't come up
		with 40 MHz.

Obviously are the server machines near their limits. The desktop
machines for the mass production have sometimes more potential.

I haven't found the crystal that drives the 3/80 yet (anyone???)

Tschuess

Peter