4790k and Noctua NHD14 Temp

[Silverwombat]

Hello @ all.
I know there are quite a few of topics with a similar question/problem. So sry for a repeating annoyance.

First of all, i bougt today a new CPU for my 2nd PC:
CPU 4790k with Noctua NHD14
MB Asus Z97
RAM 16 GB Crucial Tactics

So i ran a few tests with the new CPU (Prime95 and Aida64). With Aida the temps seem to be ok (~55-62°C). But with Prime95 they spike to 89 °C.
The point is, that in my other PC i have a 4690k (+Ashura Scythe cooler). A prime95 test doesn't exceed 65°C. Thermal paste doesn't seem to be the problem (first thing i checked). So do i have a faulty CPU, is prime95 just a program, which doesn't play well with the 4790k or is it all "normal".
The temdifference between these two CPU is a little bit high.

Thank you for the answers.

 

[GhislainG]

If you used Prime95 28.5, then you have no issue at all. It would reach 100°C and throttle with the stock cooler.

 

[Silverwombat]

ok, so its normal with the 28.5 the,. thank you.

 

[GhislainG]

ok, so its normal with the 28.5 the,. thank you.

Yes. Several members don't even dare to run it on their systems because they are afraid that it could cause issues (it doesn't since the CPU throttles when it reaches 100°C).

 

[Silverwombat]

How is the 28.6 version, is it fixed, or is it better to use 26.6? the problem is, that over the internet there are so many answers. For every post, that says "prime95 28.5 kills the cpu", there are 2 posts, where people say, that its a faulty cpu or the user should use better cooling.

 

[Neutr1n0]

Its certainly not a faulty CPU and it wont be 'fixed' with more recent versions of prime as prime is not broken. Only reason is that versions later than v26.6 run AVX instructions on the FPU which causes huge TDP and current draw on 4th gen core CPU (especially i7). Running this long periods your CPU will overheat and 'degrade' faster than usual caused by a process called electromigration which is 'stimulated' by temp and current draw.

Just use v26.6 for thermal stressing 4th gen core cpu. Read more in the sticky on CPU forum.

 

[Neutr1n0]

BTW people saying your cpu is faulty just because of high temps are usually plain idiots!

Although far from ideal implementation, cases of real nasty IHS TIM issues (internal thermal paste spreading issue) are really rare.

 

[Silverwombat]

Thanks again. It as just a kind of reassuring thread for me.

 

[GhislainG]

Thanks again. It as just a kind of reassuring thread for me.

Prime95 28.5 and newer uses the latest AVX instructions that make the CPU run very hot. Older versions don't have those instructions and the CPU runs cooler. Your CPU temperature is excellent and you have nothing to worry about.