4790k high heat problem

[rcbyan]

Hello,
I have had my system for about a year and a half, and have been battling with a CPU heat issue the entire time. According to HWMonitor, I idle in the lower 40s and rarely hit the upper 30s. Using the Prime95 small FFTs test, the temp gets to about 85. This is preventing me from overclocking, which is the reason I went with this particular chip (tried it at 4.6GHz, hit 100 degrees using P95 and immediately went back). I have a Noctua DH-15 which I have installed 3 different times, following professional videos as close as possible each time in regards to the amount of thermal paste applied. The most recent reinstall did give me better temps from before, but as you can see they are still too high. I also have a Fractal Design Define R5 case. Any help or advice anyone can provide is greatly appreciated!
Thanks,
Ryan

 

[Ecky]

It's well known that you should not use Prime95 to test Haswell and later CPUs, because AVX2 instructions cause a spike in voltage, and are not seen in general desktop workloads. Use something like OCCT instead, or just monitor it while doing what you normally do with your computer.

 

[techgeek]

You can use Prime 95 as long as you don't use anything newer than version 26.6. Everything after 26.6 uses AVX.

Another good option for stress testing is ASUS Realbench. This uses actual realworld software (not unreal workloads) to stress your CPU and because of this should produce realworld temps and stability testing.

 

[rcbyan]

Regardless, isn't idling in the 40s a bit alarming? I may be incorrect here which is why I'm asking, but that seems much too high. By the way OCCT puts me around 60, so thanks for that tip!

 

[techgeek]

I wouldn't be concerned about your idle temps. Haswell and Devil's Canyon (with the integrated FIVR) run a little hotter. It's also completely dependent on your ambient temperatures. As for your load temps, 60°C is excellent. That is only a 20°C delta.

For instance my 4770K is sitting in high 30s low 40s. Actually Core 0 is the highest, it's usually above 40 with the rest in the high 30s.

I don't think you have anything to be concerned about.

Another thing to consider is Vcore. Very often motherboards are overgenerous with Vcore. They set it high to guarantee stability and sacrifice thermals to do it. When I first assembled this system I was very discouraged to find that my Eisberg 240L Prestige wasn't keeping my CPU as cool as I'd hoped. After doing some research I found that what my motherboard was supplying my CPU with was more common for an overclock. I lowered my Vcore and found that it was stable at over .1V lower than what AUTO was setting it to.