Message-ID: <4A3D99071F51D411934C0008C7C9DEDD157949@pdxexch.paccessglobal.net> From: KirkE@paccessglobal.com Date: Fri, 23 Feb 2001 17:12:10 -0800 Subject: Overclocking Sun Ultra 30 workstation
Greetings all,
I just obtained an Ultra 30 model 300 workstation (2 18.2 GB IBM
after-market UltraSCSI) and have begun meddling with the black art of
overclocking an UltraSPARC.
I have located documentation at docs.sun.com for the jumper settings and
have discovered two important and probably noteworthy clues:
The UIIi 300MHz mbus processor module and the 360MHz mbus processor modules
no dot appear to have any hard-coded or pin-bonded frequency, which should
theoretically mean they can be overclocked assuming I can either determine
which pins represent the UPA to CPU clock divisor and (conversely) what
jumpers on the motherboard correspond to the UPA frequency (and ultimately
the divisor between UPA and PCI bus A and B).
Supposedly, with the latest OpenBoot 3.27.0, the Ultra30 can support 400 and
450MHz processors with up to 4MB of Ecache. Given the cost of a 400Mhz
processor (some $2000.00 to $2300.00), this is probably the only econonical
way to get more performance (particularly from systems like these that can
be had for $900.00 and down). If this is true, at least a few 300MHz
processors may be able to reach 360 and 400 MHz, assuming that power
requirements are not too out of whack between them (and the resulting heat
increases aren't too severe).
At 100 MHz, the UPA of a model 300 is 1/3 (divisor of 3) the frequency of
the CPU core. If I can determine if indeed there is a jumper position for
adjusting the UPA frequency to 120MHz (corresponding to a 360MHz UII module
using the same divisor), though it will may be necessary to re-adjust the
UPA to memory bus frequency back down to prevent overclocking the older FPM
memory beyond 66-75MHz.
If anyone knows what the conveniently "unlisted" jumpers on Ultra 30 are and
what clock or frequency bits these may set, please send them on. Why should
the PC geeks have all the fun? : )
I'll inform the group of my progress.
--Kirk Erichsen
This archive was generated by hypermail 2.1.0 : Wed Jun 06 2001 - 11:08:42 PDT