So, it's autumn again and I've started contributing to keeping the house warm and SPCR score increasing. I have also built a new system and retired my Prescott from folding duty.
Here's my cruncher:
http://www.silentpcreview.com/forums/vi ... hp?t=43624
I've encountered some issue with it:
1) Left it crunching, removed monitor, mouse and keyboard. Later plugged them back in and noticed monitor is stuck in power saving state, mouse and keyboard LEDs remained unlit. I don't any longer remember whether computer managed to shut down with short tap on power button (soft off) or whether I had to hard reset it. Removed monitor stand-by and haven't reoccured since.
2) I believe I've just once had that EARLY_UNIT_END & Client-core communications error. Nothing to worry about I guess since others have has similarsish problems with certain WUs.
3) There's a recurring error (or "non-error") with SMP: when I get a new WU and it starts crunching, it more often than not aborts before first 1%. Last time it aborted between 4 and 5% but that was unusual. No error message or no other line of text what so ever after last checkpoint. CPU cores just return to idle (they are not stuck in some loop or something like that). Restarting the client has always solved it.
CPU is overclocked to 3.15 GHz @1.35 volts in BIOS (SpeedFan reads lower voltage). It's Prime95 stable... well, at least 3 hours that I ran it. But I may not know for sure.
I though I was stable already at 3.2 GHz with same voltage since I had run Prime95 for around 3 hours (or whatever one complete loop takes) but later I managed to find instability when doing fan speed testing while running Prime95 to keep the heat up. Stable at 60 deg C but failed at 65 deg C.
Backed the clock a bit and kept the original voltage, remained stable under lower fan PWM setting for 3 hours. Running FAH doesn't produce nearly as high temperatures (around 50 deg C typically) so this probably should be a problem.
Now running CPU fan at 70% PWM. Temperature difference to 100% PWM is just 1 degree so it's not worth extra noise. I know OCed cores need to be kept cooler to remain stable, especially if one does not want to use higher voltage. And using higher voltage to increase stability at high temps will increase temps and so on. But how high is typically OK for a Quad at higher clocks? Do you think that 50 MHz drop actually had any difference or is it just sheer luck it didn't resurface during next 3 hours of testing? I know finding error is a hit-or-miss type of thing and nothing is really certain.
...ah, and it's definitely worth noting that SMP did make the same behaviour even at stock clock (though I had reduced voltage to 1.1 volts).
Do any of you have these silent abortions using SMP client?
In case you're curious:
with 3.15 GHz, it's pretty accurately 9 minutes per checkpoint.
And one question very off-topic:
I also now that YMMV (Your Mileage May Vary) but do systems with non-exotic cooling solution last several years crunching with 30+% overclocks? (Say, kept within 50...60 deg C so no watercooling here. Not even U120E.) If we forget about old system (since they are too easy to cool) and modern Core 2s (since they are too new to know for longterm) and focus on for example Prescotts (since they run hot), at how high clocks and temperatures have you run them (for several years - not interested in benchmark records)?