P5Q Pro Overclocking

alex24

alex24

alex24

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This is really a continuation of this thread, but it was quite confused so i'll try to summarise more clearly.

I bought an Asus P5Q Pro from OcUK b-grade, took a chance and it looks like it might be a lemon, though i'm having trouble narrowing down the problem! The board is out of the 14-day OcUK warranty, and I haven't been able to PROVE the board has an issue in this time, which I guess means game over since Asus don't deal with individuals, despite this board very possibly still having manufacturer warranty left on it.

Specs are in sig.

I currently have the board running at 400FSB with my CPU multiplier at 6, meaning the CPU is underclocked. The CPU also has a few notches over it's VID (1.35V) applied. RAM is running at stock timings, stock volts.

Under these conditions, the board is prime95 blend stable for 30sec to 3min, thus it's not stable at all. The small fft test however can run for a matter of an hour, maybe more, before it also fails. It looks like the board won't run well at it's rated FSB, which means it's bad, or am I missing something here?

The CPU was stable in my old board at stock and overclocked to 3.2 at least, it did run over for a short while with no issues. It runs cool (never over 55 deg), but the northbridge sensor doesn't seem to ever change from 39 deg for some reason. Would removing the NB heatsink and re-applying paste be a possible fix? Any way to really test the NB?

What i've tried:
Different BIOS versions.
Different RAM (2 sticks, 4 sticks)
Pretty much all BIOS settings to do with o/c'ing, including USB legacy settings.

Any suggestions on what to do now?
 
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In that case it must be just a mainboard sensor then, my mistake. Perhaps the NB is overheating? Would that cause these issues?
 
alexhull24 said:
This is really a continuation of this thread, but it was quite confused so i'll try to summarise more clearly.

I bought an Asus P5Q Pro from OcUK b-grade, took a chance and it looks like it might be a lemon, though i'm having trouble narrowing down the problem! The board is out of the 14-day OcUK warranty, and I haven't been able to PROVE the board has an issue in this time, which I guess means game over since Asus don't deal with individuals, despite this board very possibly still having manufacturer warranty left on it.

Specs are in sig.

I currently have the board running at 400FSB with my CPU multiplier at 6, meaning the CPU is underclocked. The CPU also has a few notches over it's VID (1.35V) applied. RAM is running at stock timings, stock volts.

Under these conditions, the board is prime95 blend stable for 30sec to 3min, thus it's not stable at all. The small fft test however can run for a matter of an hour, maybe more, before it also fails. It looks like the board won't run well at it's rated FSB, which means it's bad, or am I missing something here?

The CPU was stable in my old board at stock and overclocked to 3.2 at least, it did run over for a short while with no issues. It runs cool (never over 55 deg), but the northbridge sensor doesn't seem to ever change from 39 deg for some reason. Would removing the NB heatsink and re-applying paste be a possible fix? Any way to really test the NB?

What i've tried:
Different BIOS versions.
Different RAM (2 sticks, 4 sticks)
Pretty much all BIOS settings to do with o/c'ing, including USB legacy settings.

Any suggestions on what to do now?
Click to expand...

Rated FSB is 333x8=2664mhz i'm assuming (i.e 1333 mhz BUS).

Have you disabled C1E and Speedstep to make sure they are not the culprit, as well as underclocking the RAM and running Prime again?

What voltage are you giving the Northbridge?
 
OzZie said:
Rated FSB is 333x8=2664mhz i'm assuming (i.e 1333 mhz BUS).

Have you disabled C1E and Speedstep to make sure they are not the culprit, as well as underclocking the RAM and running Prime again?

What voltage are you giving the Northbridge?
Click to expand...

Thanks for the reply,

Yeah i've disabled C1E and any similar speedstep functions, also tried the RAM at below 900mhz with much the same results. It was a little while ago, so i'll double check this and try to find out.

The P5Q-E thread I will have a glance though too, though O/C's there look easy, I think there is something amiss here with the board.

EDIT: Forgot to mention, i'm giving the northbridge auto volts at the moment, though previously i've tried to bump it up to 1.44V still without getting it stable.
 
Have to set the 'CPU PPL Voltage' and 'FSB Termination Voltage' two notches above auto setting?

I'd give the Northbridge 1.3v
 
I'll do that now. I also have slackened the RAM timings and am running it at less than 1000mhz now, with stock volts, so it should be fine.
 
Yeah, dont see any reason why that wouldnt pass Prime all day long. Only other thing i can think of is loads of vdroop.
 
OK guys, i've done as you suggested and prime95 blend still fails within seconds.

The RAM is brand new Kingston HyperX PC2-8500, sure you know the stuff, i'm pretty sure it's fine, though I could swap it for some OCZ PC6400 I have here to test. However, I don't see much point in this since the RAM I had in here before was giving the exactly same isssue (that was Geil PC2-6400 ULL, and hence the new RAM), and it now works fine in another machine I have.

Is there anything else I can try? Also can someone confirm I can't send this back despite there being a chance there is warranty left on it?

EDIT: Just read the comment on vdroop, what's the best way to test that? I can see the core voltage on CPU-Z, is it just the difference between that and what i've set in BIOS or will I visibly see the voltage reading decrease under load?
 
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Yeah, memtest would show if there's RAM issues, will run now if possible.

Just added a few notches onto the CPU as it was getting 1.336V from a setting of 1.3500 in the BIOS. Now gets 1.360V. This resulted in a prime95 blend failure within seconds also.
 
Memtest86+ checked out OK, just re-testing the system now at 350FSB (2.8) to check to see if a modest O/C is ok. The board FSB is now below the rated 1600MHz (1400). However I still believe it should be able to do 400FSB, I know the CPU can as it's been on that stable for a while on a different board.

It still looks like a mobo issue. Can anyone further comment on any possible problems with the NB (and fixes?), as well as warranty?
 
Clairvoyant said:
warranty you could try asus directly.

Does it all run and pass Prime @ Stock (Bios default setting very thing on auto)
Click to expand...

As far as I know, Asus don't deal with customers directly for returns, you must go to the point of purchase (please someone correct me if i'm wrong).

I'm going to set it back at stock and see if it fails prime now. It's been stable gaming at stock since i've had it, so I have no reason to suspect otherwise. Also, is it normal for the machine to power on for a second, then power off and boot up again successfully? This only happens after having switched off mains power. Just wondered if that's a quirk of the P5Q or if something is wrong there too.

I'm only going to set FSB down to stock and test (333) as auto settings tend to overvolt a lot, especially on the CPU for some reason. I see no reason why this will produce different results. NB volts are 1.3V still, PPL and FSB term i'll leave a couple of notches above normal.
 
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OzZie said:
What do you mean by below the rated speed of 1600mhz?

Also, my P5Q Pro starts, then restarts too. It's normal :)
Click to expand...

OK, glad that's normal. I'm currently running prime at stock and all seems fine so far, I expect it will be OK for at least an hour. Overnight I may be able to test further.

By 1600 I mean the max rated FSB of the board (i.e. FSB at 400 in BIOS). Perhaps I am mistaken in my passing understanding of how this works. The board should be able to run at 400 (1600) FSB? I'm pretty sure my CPU is capable since it's been fine in previous boards. I guess I can't rule it out yet though, though if it means anything, it can run small ffts in prime for much much longer before it fails.
 
I've now done a complete CMOS reset hoping that it would help, but it hasn't. I have also put all my fans on high and cooled the case as much as possible with the hypothesis that the NB may be overheating, though this also results in instability. Perhaps there is poor contact between the NB heatink and the chip? I assume, should there be any left, removal and reinstallation of this component would void the warranty.

I'm going to find out if it can be RMA'd or not by contacting OcUK, though I strongly suspect their 14-day policy will be the limit here since Asus won't deal with me personally.
 
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