E8400 Overclocking - Temperature problems

[coolcolin09]

Hey guys!

I recently attempted overclocking my Intel E8400 for the first time after reading a few guides, including the one stickied here. I set the FSB to 400MHz for a speed of 3.6GHz. However, when I booted up again and turned on CoreTemp, the temperatures wouldn't go below 50C, and went all the way to 65C, and then to about 70-75C when I booted up Flight Simulator X. So of course, I quickly changed the FSB back to 333MHz for 3GHz. Now temps are back to 33C at idle and max of about 50C at load.

I'm just not sure why my temps are that high...I have a 120mm Zerotherm Nirvana cooler with Arctic Silver 5 Thermal paste. It seems as if it should be running much cooler. Should I get some of the paste removal and try reinstalling the fan and reapplying the thermal compound?

Thanks!

 

[Kraeoss]

did you make sure the voltage was not set to auto ?

 

[coolcolin09]

No I didn't. I suppose that would be a problem.

 

[Termie]

Coolcolin,

Try setting your vcore in the bios to something under 1.25. I run my e8400 successfully at 1.18v at 3.6GHz, which is undervolted. Another thing to do is download CPU-Z or its cousin CPUID Hardware Monitor to see what the vcore is at idle and at load. It will likely drop slightly at load.

One simple approach is to see what the vcore is automatically set to at stock 3Ghz, and try overclocking it while manually setting it to the exact same vcore. An e8400 should not require move voltage than stock to run 3.6, and could require less.

I also have a Nirvana, and I idle at about 37 in an ambient of 20 or 21, and load no higher than 55, but usually closer to 48.

 

[coolcolin09]

Thanks for the advice! I'll try that.

 

[BTRY B 529th FA BN]

Those temps are normal at 3.6 with 1.25vcore - thats what I get on my C0 8400

 

[StinkyPinky]

Anything over 70 (during load) would make me nervous.

 

[BonzaiDuck]

Did he say if he was using the stock Intel cooler?

The thermal properties of the E8x00 are similar. I have an E8600 OC'd to 4.25 Ghz. At over 75F room-ambient, LinPack stress-testing will cause the temperatures to peak between 71 and 72C. I believe the thermal limit on these processors is 71 or 71.5C. But the spec is not stated in terms of these core sensors. The spec is related to the tCase legacy sensor that informs BIOS monitor -- the point where it would ordinarily trigger throttling of the processor to reduce CPU temperatures -- as may be configured in the BIOS.

If you are not over-clocking, I think your peak temperatures would be less -- by 5 to 10C degrees.

What is the thermal resistance of Zerotherm Nirvana, or how does it stack up against a TRUE or Megahalem?

The E8x00 processors, and some of the Q9x50 series of quads, have defective core sensors -- some annoying amount of them in statistical terms. It has been reported over the last ten months since the E0 cores were released, and there was also an Anandtech article pertaining to C0 Wolfies and Yorkies, and the algorithm used in BIOS versions that addressed some fundamental difference between the Conroe/Kentsfield and the Penryn-based cores and how their sensors are read. This latter article had a section of C++ code that demonstrated the algorithm.

I have found that non-Intel BIOS's or BIOS's chosen for boards by non-Intel board-makers for some lagged market period in days or months, required revision to give proper TCase temperature reporting in BIOS monitor -- a feature common to most BIOS I know of.

To my recollection, these temperatures show something in excess of what one would expect.

My E8600 core has both core sensors (tJunction) stuck at 51C. Did it seem to me that both of your sensors are stuck at 50C? Intel has noted that the sensors are not designed to give accurate idle temperatures.

So you might see 50+C core temperatures, with the peak core values rising to 75C, but if these are the values for the core sensors, the legacy tCase sensor might be below 70C. And the thermal spec (at 71.5C) is stated in terms of tCase.

 

[OCGuy]

Absolutely do as suggested and make sure you are not overvolting on Auto.


As far as the voltage suggestion someone mentioned, please ignore it. Just because someone has thiers stable undervolted does not mean you will.


Go through the proper steps of figuring out what is a stable vcore for your overclock. My C0 E8400 needed 1.3v for 3.6ghz.

 

[Piano Man]

Something's up with those temps. With that case and HS&F, you should be getting lower temps unless you just got extremely unlucky with that CPU.

Definitely check your core voltage. I'd start with 1.3V and back it down a notch until you can't run Orthos or Prime95 for an hour or so.

You may want to try and reseat the HS&F as it may not be getting good contact. Also can you see the RPM on the CPU fan? I wonder if its running slow.

I've got an 8400 E0 running at 4.5Ghz@1.3275V with a TRUE paired with a Scythe S-Flex "F" Fan. My case is also bigger with more airflow, but not enough to justify the difference in temps. At 4.5GHz, Orthos never pushes my temps above 56C. Room temp is probably 75F.

1. Look at the C2D OC thread http://forums.anandtech.com/me...=2057083&enterthread=y
2. Check that vCore setting
3. Might have to reseat the HS (make sure to use just enough AS5 to barely cover the CPU.)