"baj2k" wrote in message...
I have an ABIT IS7 motherboard with a P4 3GHz/1MB over clocked
and stable at 267Mhz.

That's a good overclock!

Bus setting: 267/76/38

As a general point, you'd be better off locking the PCI and AGP buses at
33/66. Running an overclocked PCI bus doesn't gain you any significant
performance nowadays, and can cost you in component (primarily hard disk)
reliability.

Memory: 5:4 (512x2 DDR PC3200) someday I'll get PC4000 and
try 1:1

You're actually losing quite a bit of overall system performance by running
the async memory bus. As you say, PC4000 (or maybe better PC4400) is the
perfect answer, but you may find that, if your current memory will run a
little faster than it is ATM, it's possible that the best performance
compromise may come from running 1:1 at a lower FSB. Doing it that way would
also reduce the CPU's power demand, which would make the power supply
circuitry happy if nothing else!

Temperature at load (Prime95 maximum torture setting):
Sys: 37c | CPU: 75.5 +/- 5c | PWM: 75.0 +/- 5c

That PWM reading is very, very hot. Unsurprising given the amount of current
the CPU will be pulling under load. It's also possible that the CPU is
throttling, cutting back the performance. You can check this by downloading
ThrottleWatch and leaving it run during periods of extended intensive
utilisation.

Are these settings and temperatures safe?

I'd be uncomfortable running this system with the PWM temps as high as they
are, while I'd also want to check for CPU thermal throttling before deciding
whether the existing thermal solution on that was sufficient.

At minimum I'd be thinking about heatsinking the power MOSFETS and directing
a source of cold air directly onto that area of the board.

Am I walking on thin ice, or living on borrowed time?

Questions like that are always almost impossible to answer with certainty or
evidential backing, unless you're a motherboard manufacturer with access to
proper test data. Which, of course, none of us are.

Any suggestions on a better heatsink fan combo

There are a few heatsink/fan assemblies that'll do a better job than the
stock product supplied with the CPU. Difficult to suggest one in particular.
--


Richard Hopkins
Cardiff, Wales, United Kingdom
(replace nospam with pipex in reply address)

The UK's leading technology reseller www.dabs.com