Hello, I am currently running my Q6600@3.0GHz (9x333 w/ Memory Running @ 1066MHz) on an Asus Rampage Formula with a Corsair 620w PSU. I am also running a GTX295 - 3 HDDs - 1 DVD Burner. When I overclock to 3.6 GHz (9x400 w/ Memory @ 1066MHz w/ CPU voltage at 1.45v) and I run CPU-Z with Prime95 the process fails on 2 of the 4 cores (0 and 2 mainly). I notice that in CPU-Z that the voltages goes from ~1.4v to about 1.36v as soon as prime starts - shortly after prime starts to give me errors. Is this a Voltage drop from my PSU? Any tips on what I might need to tweak in order to get this to run stable - I tried upping the North Bridge Voltage slightly (1.65v) didn't seem to make any difference - I also dropped my memory clock to 800MHz - still failed. Thanks in advance
Could possibly be a weak rail on the psu, not suppling the right amount of voltage. What you have to remember is that the cpu is being fully loaded, which wouldn't happen in normal use. The problem is if you add more voltage you run the risk of frying your cpu. Another thing that could be happening is that, although the overclock you've got running seems stable , when prime maxes everything out it's proving not to be totally stable. Try reducing the overclock and run it again and see what happens.
its called vdroop - its normal. in your BIOS look for a setting called load line calibration - this compensates for the drop in voltage.
I would say your overclocking it to much. Unless your temps are in order then I would say its something else. I would say pump it up higher, but watch those temps. It sounds like its going unstable due to either temps or not enough power. And why are you pushing it so hard? The stock on that thing is only 2.4, your pushing the line aggressively on it (30% more then stock). I got stable on my Q6600 at around 3ghz.
I'm assuming a a G0 stepping ? What vid is the cpu ? My q6600 could run stable at virtually volts ( 1.3v ) 3.6ghz (9x400) with ease. a 1.25 vid chip.
I had a similar problem a while back which was causing instability with my cpu (also a Q6600 running at 3.8ghz) and I changed my PSU which solved the problem..How old is your PSU?
Yes it is a G0 Stepping - The VID is 1.2750v - The temps are not exceeding 55C at full load My PSU is older (I would say 3 years or so - but it's one of the Corsair PSUs before they started making the cheap ones they make today - I do understand that it degrades over time though - so it might just be time for a new one) I really just want to clock this up to buy some more time - and I know some people can get seriously good clocks like the dude who said he's running at 3.8 GHz I will see if it has a setting like "load line calibration" - thanks for the tip dude I will fill you in on my results Thanks everyone
barndoor101 you rock dude - that was the setting that needed to be turned on - I was able to sneak by with 1.4v and prime was fine - the only downside is the cpu was running at 77C - looks like I might need a better cooler than the OCZ Vendetta - perhaps it's time for watercooling
Ghost Thread I recently bought a Q6600 GO and I had the same problem when I Overcloked, But it was only 1 core. In a first time I was surprising but after reflexion I simply increased the Vcore and now its gone. Do you think this voltage is good for 3.2Ghz ?
That voltage is fine. The VID on my Q6600 according to CoreTemp is 1.325, so your fine. I've got mine at 3.2GHz with CPU-z reporting 1.328V. Temps never go above 55'ish, if I turn all fans up to full, it'll be around 50'ish. idle can be anywhere from 35 - 48 depending on which fans I have on.
I knew how worked my previous CPU but this one is too recent for a mutual comprehention, that's why I asked (Thx). It passed the last year in a house PC, Unoverclocked ! What a shame ...... Now the foal is in my hand, I will unleashed it. 3.24Ghz is fine for me, its in the safe zone without too much Tweak About the Temps, with my new fans configuration, the thing is between 30-33 in idle.
LLC - Loadline Calibration - does not always work very well, some recommend to leave this option disabled (Anandtech). There is also an option for enthusiasts... the pencil mod.
