i7 940 Temperature Question

[wbo]

I just built an i7 system using a Gigabyte EX58-UD5, 12GB of OCZ XMP DDR3 1600 RAM, and an i7 940 CPU. I am using a Noctua NH-U12P HSF in an Antec P180 case. I am using both fans on the heatsync in a push-pull configuration and the Noctua compound that came with the heatsync.

The Tricool fans that were originally in the P180 have been replaced with 4 Noctua NF-P12 fans with the low noise adapters inline to reduce their RPM to 1100 RPM. I have one fan mounted in the front of the case drawing cool air in, fans located in the top and the back of the case drawing air out, and a fourth fan in the bottom chamber drawing air over my hard drives. This case setup worked quite well for my previous q6600 build.

I am aiming for a relatively quiet system and I do not plan to overclock much, if at all. I choose the Noctua heatsync because the reviews I read on it indicated that it should be quite capable of keeping a 940 CPU cool with very little noise.

After putting everything together I am very pleased with the performance of the system but I am getting concerned about the temperature of my CPU under load. My CPU idles at 46-47 C and reaches 81-82 C under load with 8 threads of Prime95. If I run 8 threads of Prime95 along with LinX the temperature reaches 92 C. All temperatures are measured with RealTemp. Ambient temp was around 22 degrees C.

I was initially running both heatsync fans using the low noise adapters but taking the adapters out only dropped the load temperature 1-2 degrees which is consistent with the reviews I have read.

I know the i7 CPUs typically run fairly hot but I never expected that an i7 940 at stock clocks would exceed 90 C. Is this normal? I expected to see temperatures in the upper 70’s or low 80’s under load. I tried reseating the HSF but the temperatures did not change.

 

[sirmonkey1985]

using prime95.. sounds about right.. your real full load temps on an every day app will be more like 65-70C

 

[Plumber4life]

Your temps actually seem pretty good for that 940 considering how low speed you have youre fans at. My 965 idles @ 33 to 34 Clocked 4.45 and @1.515 volts and running themalright extreme 120 with 3000 rpm fan dont worry looks good.

 

[echn111]

Unless the i940 runs much hotter at stock than an overclocked i920, that doesn't look like an average load temp. (don't care about your idle temp as it's not relevant)

I get 76 to 78c with 8 cores being stressed by Prime95. Unlike your stock CPU, this is slightly overclocked to 3.6Ghz. Also unlike you, I am actually using passive cooling . Specifically a Thermalright HR+ with no active fan, although I do have a duct and a rear chasis fan running at 800rpm. I admit that if I put a noisy 1200 rpm fan on the cooler, my load temps go down to the 60's, but I'm into quiet computing and cannot stand the noise of any fan over 800rpm.

Anyway, an i940 at stock with "two" noisy fans running should not be getting higher temps than me.

Could be low airflow, perhaps your case is very messy inside. Or the way you set the TIM. Up to you. On the positive side, even if your temps are well above average for most people with "stock" i920's, if it's stable you could just live with it.

 

[echn111]

Quick/easy suggestion: redo the test with the case open in a reasonably well vented area (or use powerful case fans) to remove the poor airflow variable.

If you see a drastic decrease in temps you know there is a good chance case airflow is the problem. Could be due to a messy/cluttered case severely restricting airflow or if you're using fans with poor static pressure capabilities in a case that restricts air movement (i.e. fans move air well if unrestricted, but have a lot of problems moving air in a restricted environment).

If not, the issue is likely with your CPU/heatsink setup.