To the list,
Irecently got a second PWS500a/u, this one a GL model with the USB
ports. I'd heard that the Miatas can be overclocked and decided to
try it with the older machine.
I got a list of jumper settings posted on comp.sys.dec August 15, 2002
by Marco Nuessgen. I eBayed a 533mhz cpu as a spare, it arrived today
so I decided to try o'clocking it.
I put in the 533 (it has a PC 164 heat sink on it) with the Miata heat
sink, and set the jumpers to what was supposed to be 600 mhz.
The setting I used is below:
00000101 1 being up and 0 being down, relative to the bottom of the
Show Config indicated the CPU was running at 533. I tried booting
Linux, the kernel got lost looking for the PCI bus. I took the CPU
out. It was pretty warm, considering it had been running a few minutes
under light load.
I put the old CPU in with heat sink. It ran a lot cooler but still
would only go 533. I didn't bother trying to boot, alhtough I bet I
could've got Windows 2000 to come up off ARC.
I noticed that the little silver heat transfer sheet, which had never
melted under the 500 cpu in 5 years of active use, had fused to the
new 533 CPU.
Marco's post showed the following jumper settings
does anyone know if these are right? If so, are my CPUs somehow
internally limited for clock speed?
Unlike on a PC, changing the CPU frequency on the Miata seems to
change some IRqs as well as PCI and memory frequencies. So I guess a
successful overclock means some pretty serious reworking of my Linux &
Tru64 OSes, maybe even a rip-out and re-install?
Well, has anyone else tried this? How did it go?