Question i5-9600k/Noctua NH-D15s High Idle temps but decent gaming performance?

Aug 8, 2019
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Recently completed a build with an i5-9600k and a Noctua DH-15s. My idle temps when on my desktop are around 40-50c, idle temps when in bios around 35c. From what I've seen online these idle temps are a bit high. However, my gaming performance has been pretty acceptable, never going over 55c even when under full load playing the most demanding games I own. So I'm not really worried about anything catching fire, I guess I just expected there to be a bigger delta between my idle and gaming temps. For reference my ambient temps around this time of year, in the room my computer's in anyway, are around 20-25c.

Maybe this is nothing to worry about, but I wanted to make sure.

edit: I'm going to run Prime95 for 10 minutes to make sure things are ok under maximum load, what is a safe temperature range? I'm not sure what to expect as I haven't used this software much
 
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jay32267

Champion
"I'm going to run Prime95 for 10 minutes to make sure things are ok under maximum load, what is a safe temperature range? "


I think this is a good idea.

Ideally you want it below 70C.

If it stays under 70C....I wouldn't be concerned about the high idle temps.
 
Aug 8, 2019
34
3
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"I'm going to run Prime95 for 10 minutes to make sure things are ok under maximum load, what is a safe temperature range? "


I think this is a good idea.

Ideally you want it below 70C.

If it stays under 70C....I wouldn't be concerned about the high idle temps.
alright, will do; thanks. I've heard that certain newer versions of prime95 should not be run with newer cpus; what version of prime95 would be safest for me to run with an i5-9600k
 

jay32267

Champion
I've heard various things like that about some of the benchmarking tools.
Although I don't really keep track......so maybe google around.
I've used CPU-Z to benchmark CPUs. It's probably not the best....but it does what I need it to do....and I've only done it a few times.
 
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CompuTronix

Intel Master
Moderator
I've heard that certain newer versions of prime95 should not be run with newer cpus; what version of prime95 would be safest for me to run with an i5-9600k

Doctor Thoss,

On behalf of Tom's Moderator Team, welcome aboard!

There's no need to Google around. We actually have a Guide that covers this topic. It's a "Sticky" near the top of the CPUs Forum, so if you look you can't miss it. Read the entire Guide, but pay close attention to Section 11 - Thermal Test Basics:

Intel Temperature Guide - https://forums.tomshardware.com/threads/intel-temperature-guide.1488337/

To answer your question, the issue to which you're referring concerning Prime95 is specifically the AVX codes that runs on the processor's AVX instruction Sets.

You need to run the latest version of Prime95, which is 29.8:

• Prime95 v29.8 - https://www.mersenne.org/download/

Click on the boxes for AVX2 and AVX to disable those AVX codes. Run only Small FFT's. 10 minutes is more than adequate to give you a valid thermal baseline.

The following is from the Guide:

"Prime95 v29.8 Small FFT's (all AVX selections disabled) is ideally suited for testing thermal performance, because it conforms to Intel's Datasheets as a steady 100% workload with steady Core temperatures. No other utility can so closely replicate Intel's thermal test workload."

"AVX - Advanced Vector Extension (AVX) Instruction Sets were introduced with Core i 2nd Generation CPU’s, then AVX2 with 4th Generation and AVX512 with later Generations of High End Desktop (HEDT) CPU’s as in certain X-Series, Extreme, i9’s and i7’s. Running versions of Prime95 with AVX enabled imposes an unrealistic 130% workload which can adversely affect stability and severely overload your CPU. 2nd and 3rd Generations are less affected, but Core temperatures on 4th through 9th Generations may be over 20°C higher.

Many 6th through 9th Generation motherboards address the AVX problem by providing “offset” adjustments (downclock) in BIOS. -3 (300 MHz) or more may be needed to limit Core temperatures to 85°C. Since 4th and 5th Generations don’t have AVX offsets, you can create individual BIOS Profiles for AVX and non-AVX software. Except for a few utilities and specialized computational apps, AVX intensive real-world apps (rendering, transcoding) and recent games with AVX shouldn’t exceed Prime95's test workload without AVX.

As per Intel’s Datasheets, TDP and Thermal Specifications are validated “without AVX. In Prime95 versions from 27.7 through 29.4, AVX can be disabled by inserting CpuSupportsAVX=0 into the local.txt file, which appears in Prime95's folder after the first run. However, since Core temperatures will be the same as 29.8 without AVX, it's easier to just use 29.8. You can also use 26.6 which doesn't have AVX. Core i 1st Generation, Core 2, Pentium and Celeron processors don't have AVX Instruction Sets, so they're not affected."

"Here's the nominal operating range for Core temperature:

Core temperatures above 85°C are not recommended.

Core temperatures below 80°C are ideal."



Once again, welcome aboard!

CT :sol:
 
Aug 8, 2019
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Thanks for the very detailed response! I installed a 2nd intake fan that I'd ordered with the other parts but that didn't arrive until today, which brought my average idle temps down to around 33-37c, then I ran prime95 on Small FFT's with all AVX options disabled for 15 minutes. The highest core temp I hit during the test was 63c, which afaik is pretty good. So I think I'm all set, thanks again!
 

CompuTronix

Intel Master
Moderator
Doctor Thoss,

There's a few additional considerations I would like to bring to your attention.

In order to level the playing field so we can compare apples to apples, it's necessary to minimize as many variables as possible. Unfortunately, many users apply the term "idle" very loosely, where "idle" is instead a light workload. When combined with differences in ambient temperatures which are all too often not mentioned, this why you see so much variation in idle temperatures on forums.

Idle means minimal software activity where you leave your rig to settle quietly and undisturbed for at least 10 minutes. No programs or screensaver running, and off line. No Folding or SETI or "tray-trash" or unnecessary startups, processes and services running in the background, and just 1 or 2% CPU Utilization under the "Performance" tab in Windows Task Manager.



Under these conditions, in a well ventilated case with default power saving features enabled in BIOS and Windows Power Options set to "Balanced", you should be able to achieve the lowest possible power consumption and idle temperatures.



With high-end cooling, idle can be as low as 3°C above ambient, which was 22°C when this screenshot was taken.

CT :sol:
 
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