More vcore needed to pass prime blend?

JonJ678

JonJ678

JonJ678

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Hello all. I think my computer is behaving slightly strangely. It'll pass small fft for ages, but crashes on blend almost immediately. The solution is nearly always more Vcore, with northbridge voltage helping very little, and more ram voltage helping a bit.

I think this is very odd, as I thought failing small => +vcore and failing blend => more northbridge. Any thoughts?

Only at 411 fsb or so, the board behaves fine up to 475 on a x6 multipliar.

(P5Q, q9550, 4 sticks of ram)
 
I've been raising the fsb term roughly alongside northbridge voltage so far, which worked fine up to 3.5ghz. Northbridge is at 1.24, fsb term 1.18 at present I think. Vcore is at 1.32 though which seems far too high for 3.5ghz.

It stops being stable if I take the vcore down at all, but I'm wondering if less vcore matched with more nb and fsb term would also be stable. Testing at present
 
You may need to up the pll, fsb annd nb voltages a bit, for my q6600 (albeit an older 65nm cpu) i needed the following,

cpu pll, 1.6
fsb-term 1.34
nb, 1.3

The above are all within safe limits for either 45nm or 65nm cpu's.
 
Up a notch on either nb or fsb term gets me from 0 minutes to 1 on blend. Doing both gets me to 2 minutes.

Bizarrely the thing that makes the most difference is RAM voltage. Moved from 2.00 to 2.02 and blend is quite happy 10 minutes in rather than crashing after two.

I find this worrying, as it seems strange that ram rated at 1066mhz at 2.1V should be incapable of 830 at 2V. Timings are all on auto, setting them manually to ridiculously loose doesnt seem to help at all.

Does that mean anything to either of you?

edit: 20 minutes in with the +0.02V ram
 
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Regarding your memory voltage, if your ram is rated at 2.1v, its advisable to set it to 2.02v. This is due to the p5q boards overvolting the ram by 0.08v. Ive had to do this with my previous ocz reaper 6400 and my current reaper 8500.
 
Ah. In that case, while the ram at 2.02V seems to have solved stability problems, I won't push it any further. This is unfortunate, since I expect the easiest route to stability at 3.6 is going to involve more Vdimm.

Where did you find out about the overvolting? Is that applicable to 2x2gb sets, or also to 2x4gb sets? I don't know how the circuitry in the board is organised. Introducing more components means more voltage dropped across each one and so more voltage must be supplied, so its possible that the +0.8V is only applicable to one configuration.

Also, the damn things just failed at 34 minutes.

edit: tried fsb term up to 1.24 to match nb, and it fails within about 4 seconds. i start to remember why i left this at stock after my last attempt
 
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A member of extremesystems forum tested the boards with a multimeter and discovered this about the ram, also that the pll, fsb term and nb volts overvolted quite a lot if left on auto or the lowest manual setting, so it was advised to set theese to +0.02v above auto when starting any oc. Those were the settings i used to take my quad to 3.6ghz, i needed more signifigant increases on the chipset voltage though for 3.8ghz (9x422) Also when running with all 4 memory slots filled the nb usually needs a boost in voltage to help with stability.
 
Overvolting on auto I've met before, while fair enough on auto it's a bit frustrating that the minimum setting is treated the same. I couldn't find a source for the ram overvolting, just many referances to it. Ill go and have a look through extreme forums. I've also asked ocz about it.

I appreciate the clarification setter. There's a seemingly mystical link between electronics and computer hardware that I haven't really got my head around yet. I fear that they're basically much, much more complicated than logic gates or op amps :)
 
It was a guy known as jvidia on xs who done the initial testing on early release bios rev p5q boards. His findings were in this screen shot that was posted on the p5q thread here on ocuk.

p5qdeluxe0702vreadingscrj5.jpg


It says p5q deluxe but i think its safer to assume this with all p5q boards
 
Which bios rev are you on iamateaf? Im still on 0803, which is pretty early but has been extremely stable for me, but thanks for the heads up on newer versions improving this.:)
 
Oh good. That clarifies things. The answer may be to find out where he took the measurements from and use a multimeter myself.

Well, current settings.
FSB 420
Vcore 1.325
PLL 1.52
Vtt 1.22
nb 1.24
ram voltage 2.02

This is not stable. If i increase *any* of the above five voltages a single notch it becomes significantly less stable. Buggered if that makes sense, apparently I need to decrease some of these. I'm going to sleep instead however. G'night
 
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