Q6600 throttling even w/o C1E, SpeedStep

[Jut]

Hi, I've recently purchased a Q6600 to replace my E6550 and I decided to do a bit of overclocking with it.

I've reached the point where I'm testing stability at 3.2 GHz with the following settings:

FSB: 356
Multiplier: 9x
Vcore: 1.2675
DRAM multiplier: 1:1
DRAM voltage: 1.8V

Speedstep Disabled
C1E Halt State Disabled

It has been stable under Prime 95 for over 3 hours now (just started testing a while ago). It also passes Intel's Burn Test with 5 runs at maximum. However, the problem is, I was monitoring the temps and clock speed during the stability testing, and I noticed that the multiplier goes down to 6x during Intel Burn Test at random times. Initially I thought it was running too hot, but IIRC throttle temp for the Q6600 is 100 degrees, and my maximum temp was only 70 degrees (using push-pull Hyper TX3, ambient around 28C). I re-checked the BIOS and Speedstep and C1E were both disabled so my CPU should stay fixed at 3.2 GHz.

I did, however, try disabling CPU TM function. Now I know that this is the CPU safety feature that throttles down your CPU when it gets too hot, but if I'm not mistaken, this throttling should happen at around Tjmax, which is somewhere over 100 degrees. I noticed that the throttling happens at around 70 degrees which is nearer to Tcasemax (71C), but it's still over 20C lower than Tjmax.

Right now I'm testing 3.3 GHz at 1.31V, max Intel Burn Test temps are 73 degrees.

Is it wrong to have disabled CPU TM function? 70+ degrees isn't all that bad yet, is it?

 

[gramboh]

There are sometimes offset problems with the monitoring software versus the actual temperatures. That said, I've had my Q6700 (same chip basically) with cores into the low 70's and had no throttling. I run at 1.45V for what it's worth it, 24/7 (Speedstep/C1E disabled) for 3.5 years now, so I wouldn't worry about your temps.

 

[Jut]

With that said, are you saying I should just leave the TM function off?

 

[gramboh]

It shouldn't be necessary, I have it on, and have never experienced that kind of throttling, even with core temps into the 80s during burn test. That said, if you are confident in your temps during benchmarking I would turn it off to avoid the throttling if you want to keep your OC.