Too low voltage or is Something over heating?

[rob_cunningham]

i am trying to get my Q6600 to a stable 3.6ghz.

My best effort so far is stable under normal running (web browsing, etc) but only 5min in Prime.

I tested a slight increase in voltage and got worse results (vista wonldn't get much past log in) and this repeated for a few further increases. Because of the lack of improvement from the voltage increase i decided back to the last settings that worked the best but these wouldn't get much further past the log in screen either.

Is this because the voltages i am using are using just high enough to run and therefore a little unstable? Or is something getting too hot causing the system to fail earlier after continued use/trial & error.
Bios temps show CPU at 40deg and motherboard at 45 deg. HW Monitor reads cores at approx 40-45 idle but i don't know which temps are for my NB and SB.

My Specs are:
Asus P5N72-T Prem'
Q6600 (G0) VID 1.2500v
2x 2gb OCZ Reaper 1066

Settings:
Fsb 400
Multiplier x9

CPU: 1.40v
PLL: auto
VTT: 1.24v
Mem: 2.1v
NB: 1.52v
SB: 1.55v
1.2 HT: 1.25v
GTL_REF: +50mv

Thanks for any help in advance.

 

[dagger]

40C is hardly too hot. Although you should test with prime95 to find out full load temperature. Thermal threshold is 71C, keep it below that.

As for vcore, Intel's recommended voltage for q6600 is 1.5v, which means it's absolutely safe to go up to at least that much. Different cpus tolerate voltage differently, for duals like e8400, it's 1.3v. Slight overvolting is okay, but you should not overvolt by more than 0.1v past official recommendation.
http://processorfinder.intel.com/details.aspx?sSpec=SLACR

Turn on Loadline Calibration if supported.

Also, downclock the ram to 800mhz, for 1:1 ratio at 1600mhz fsb, to rule it out as possible cause for instability.

 

[rob_cunningham]

Yes, sorry i should have mentioned that i do have Loadline calibration enabled - this made a huge differnence to running at a higher fsb.

When it was working at the above settings i was able to run Prime for about 5min before it crashed (screen hang) and i had to reboot. Highest temp was somewhere around 60C according to Core Temp.

I did find some settings that were sucessful with a vcore at 1.5v, I only ran Prime for 2min because temps just >70C.

I am pretty confident i can get stable at 3.6 but i think my mobo is very picky on its voltage settings. e.g. if i just raise the the CPU voltage it quicly becomes unstable unless i raise the others to suit. Is this normal?

naturally i want to find a stable ground at 3.6ghz with the lowest voltages possible.

My ram is 1066mhz at stock and i am using all reccommended voltages and timings. I have ran memtest for and came up with 0 errors (only for an hour) with other bios settings set for cpu 3.6ghz. If i ran memtest for longer would it rule out this possibility of being the problem or is it just better to run ram at more simple ratios?

Would you suggest linking the memory at 1:1 ratio or setting it manually at 800mhz?

Sorry for all the questions, I am new to this and trying to learn fast and often trying to swim way out of my depth.

Look forward to your reply.

 

[Zecow]

I got my Q6600 to 3.6 Ghz - with 1.45v. At 3.8Ghz 1.55v As for temps, its not the idle you should be concerned.

Try changing to 450x8 - My board doesn't like 400x9, but doesnt mind me pushing it to 475x8. It might work.

My VTT is at 1.52, NB at 1.38, SB default

 

[rob_cunningham]

Thanks for the info. I'll try 450x8 and let you know.

Do you have the same Mobo?

I may have a ram error afterall. just tried installing a game, twice and both times i was given a BSOD - one just said harware malfunction, other said same but also "NMI: Channel Check / IOCHK" which apparently may be linked to memory.

I am going to first try a long period on memtest and see what this brings up and if there's a problem then i'll look at replacing my modules.

 

[Zecow]

I got the Asus Rampage. Use single channel first and test each stick at a time. Are you OCing while installing the games? If so, the system might not be stable yet.

What cores are getting errors in Prime? Normally there are GTL_REF#1 and GTL_REF#2 (GTL_REF#1 controls core 1/2, and GTL_REF#2 controls core 3/4) I'd leave them as default for now. Only adjust them 1 increment at a time according to each core failure.

 

[rob_cunningham]

I've sucessfully OC'd @ 3.0ghz - ran prime95 on all 4 cores for over 24hrs with temps not exceeding 50C. this is what i am using at present and what i was running at to install games. However, i did flip SpeedStep on last week to see how system would run maybe this is the issue?

I have only a single GTL_REF, i did find that this made a big difference to running previously at 3.6ghz. I ran Prime with it set to Auto and got 2min before it crashed. I then set it to +50mv and got near 5min before crashing. System ran noticably quicker too. I haven't tried setting to Default. Does this make a difference from Auto?

When Prime Crashes my screen just hangs, i get zero activity on HDD or any other sign of system still running. I haven't recieved any core failures in prime (i do check each time i run that round off checking is selected.

 

[soark]

My to.. when I stress test my Q6600 @ 3.2 or 3.4 in prime95 (all 4 threads) it does not gives errors...it just gives me a BSOD :S if the voltage is high enough it just passes the tests..it never fails

I have a MSI P35 Platinum and overclocking with 4*1 GB ram,should i test only with one stick?

 

[rob_cunningham]

I've just tested my memory for nearly 3 hours using memtest and it didn't come up with any errors.

I had my memory set to 1066 and CPU to 3.6ghz. I am assuming i can rule out any possibility of there being a memory problem that is affecting my OC.

I'll have a go at ZeCow's suggestions of increasing the VTT and CPU voltages.

 

[rob_cunningham]

I think I may have found some stable ground using the following settings:

CPU: 1.4375v
PLL: Auto
VTT: 1.46v
Mem: 2.1v
NB 1.52v
SB: 1.55v
1.2 HT: 1.25v

GTL_REF: +50mv
Loadline: enabled

I first tried just increasing the Cpu voltage but this just became more unstable. I then added some extra Voltage to the VTT and this improved things a lot.

Seems to be ok under normal running for last few hours. Also ran 3dmark06 which gave me an 850 point increase over stock. Core temps idle at 42-47C yet to test under load. CPU-Z reads vcore at 1.376v.

I will test in Prime in the morning. I will try to get voltages down if possible but i'll see how she goes from here first.

 

[rob_cunningham]

Ran Prime. Temps spent most of the time at 71c on cores 0&1 and 66-67 on cores 2&3.

Core 2 failed at 1hr 26mins.

Any suggestions on what to do next?

 

[soark]

Back down the OC or change the cooling to something better (Best of air or water)
Maybe settle with 3.4?
A that temps you will fry or cpu very fast :S
Personally anything above 65 is to much!