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I7 4790k - Prime95 High Temperatures ?? (H110)

Howdy great peeps,

I've gotten new fans for my H110 cooler & re-applied NX-4 thermal paste (correctly),
but when I run Prime95, the second I start the application, the temperatures go to 80c.

Is this acceptable whilst running Prime95? I have NOT overclocked it.
(The new fans I got are a pair of Noctua NF-A14 IndustrialPPC 3000)

I am using the latest version of Prime95.

Kind regards,
Mike
7 answers Last reply Best Answer
More about 4790k prime95 high temperatures h110
  1. 80C is warm but normal for this type of stress testing, just make sure your using version 26.6.
  2. You have had an existing h110, replaced thermal paste, fans and continue to have the same thermal results?
    This leaves the problem to be the pump, air flow in the case and or radiator positioning.
    Have you always had this problem?
  3. Normal temps for stress testing in Prime 95.
  4. Best answer
    DutchMike,

    This is a widely known problem. As WildCard999 has already suggested, run only Prime95 version 26.6. Here's why:

    2nd through 8th Generation i3, i5 and i7 CPU's have AVX (Advanced Vector Extension) Instruction Sets. Prime95 versions later than 26.6 run AVX code on the CPU's Floating Point Unit (FPU) which causes unrealistic temperatures up to 20°C higher due to excessively high TDP workloads.

    Here’s a sample of utilities grouped as thermal and stability tests according to % of TDP, averaged across five Generations of processors at stock settings:

    TDP ... Thermal Test - Steady Workload

    129% ... Prime95 v27.7 through v29.4 - Small FFT’s (AVX, No Offset)
    101% <-- Prime95 v26.6 - Small FFT’s
    89% ... HeavyLoad v3.4.0.234 - Stress CPU
    87% ... FurMark v1.19.1.0 - CPU Burner
    78% ... CPU-Z v1.82.0 - Bench - Stress CPU
    66% ... AIDA64 v5.95.4500 - System Stability Test - Stress CPU

    TDP ... Stability Test - Fluctuating Workload (Peak)

    123% ... OCCT v4.5.1 - CPU: OCCT (AVX, No Offset)
    118% ... LinX v0.6.5 - Default
    116% ... IntelBurn Test v2.54 - High
    113% ... OCCT v4.5.1 - CPU: Linpack (AVX, No Offset)
    110% ... AIDA64 v5.95.4500 - System Stability Test - Stress FPU
    99% <-- Asus RealBench v2.56 - Stress Test (AVX, No Offset)
    97% ... Intel Processor Diagnostic Tool v4.1.0.24 - Default
    94% ... Sandra 2017.09.24.41 - Burn in - Processor Tests
    92% ... CineBench v15.0 - CPU - Render Test
    79% ... Intel Extreme Tuning Utility v6.4.1.15 - CPU Stress Test

    All tests will show 100% CPU Utilization in Windows Task Manager, regardless of actual Workload. Higher TDP tests produce higher Core temperatures. Power (Watts) and Core temperatures will vary with Microarchitecture, Core count, Core speed, Core voltage, VID, Turbo Boost, Hyperthreading, Instruction Sets, Memory, IGPU, CPU cooler, BIOS versions and Microcode.

    AVX can be disabled in Prime95 versions later than 26.6 by inserting "CpuSupportsAVX=0" into the "local.txt" file in Prime95's folder. However, since Core temperatures will be the same as 26.6, it's easier to just use 26.6.

    Many 6th, 7th and 8th Generation motherboards address the AVX problem by providing offset adjustments in BIOS. However, motherboards that support 4th Generation processors do not have AVX offset adjustmets.

    Download Prime95 and run only Small FFT's for just 10 minutes.

    • Prime95 v26.6 - http://www.mersenneforum.org/showthread.php?t=15504

    You might want to read this: Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html

    CT :sol:
  5. CompuTronix said:
    DutchMike,

    This is a widely known problem. As WildCard999 has already suggested, run only Prime95 version 26.6. Here's why:

    2nd through 8th Generation i3, i5 and i7 CPU's have AVX (Advanced Vector Extension) Instruction Sets. Prime95 versions later than 26.6 run AVX code on the CPU's Floating Point Unit (FPU) which causes unrealistic temperatures up to 20°C higher due to excessively high TDP workloads.

    Here’s a sample of utilities grouped as thermal and stability tests according to % of TDP, averaged across five Generations of processors at stock settings:

    TDP ... Thermal Test - Steady Workload

    129% ... Prime95 v27.7 through v29.4 - Small FFT’s (AVX, No Offset)
    101% <-- Prime95 v26.6 - Small FFT’s
    89% ... HeavyLoad v3.4.0.234 - Stress CPU
    87% ... FurMark v1.19.1.0 - CPU Burner
    78% ... CPU-Z v1.82.0 - Bench - Stress CPU
    66% ... AIDA64 v5.95.4500 - System Stability Test - Stress CPU

    TDP ... Stability Test - Fluctuating Workload (Peak)

    123% ... OCCT v4.5.1 - CPU: OCCT (AVX, No Offset)
    118% ... LinX v0.6.5 - Default
    116% ... IntelBurn Test v2.54 - High
    113% ... OCCT v4.5.1 - CPU: Linpack (AVX, No Offset)
    110% ... AIDA64 v5.95.4500 - System Stability Test - Stress FPU
    99% <-- Asus RealBench v2.56 - Stress Test (AVX, No Offset)
    97% ... Intel Processor Diagnostic Tool v4.1.0.24 - Default
    94% ... Sandra 2017.09.24.41 - Burn in - Processor Tests
    92% ... CineBench v15.0 - CPU - Render Test
    79% ... Intel Extreme Tuning Utility v6.4.1.15 - CPU Stress Test

    All tests will show 100% CPU Utilization in Windows Task Manager, regardless of actual Workload. Higher TDP tests produce higher Core temperatures. Power (Watts) and Core temperatures will vary with Microarchitecture, Core count, Core speed, Core voltage, VID, Turbo Boost, Hyperthreading, Instruction Sets, Memory, IGPU, CPU cooler, BIOS versions and Microcode.

    AVX can be disabled in Prime95 versions later than 26.6 by inserting "CpuSupportsAVX=0" into the "local.txt" file in Prime95's folder. However, since Core temperatures will be the same as 26.6, it's easier to just use 26.6.

    Many 6th, 7th and 8th Generation motherboards address the AVX problem by providing offset adjustments in BIOS. However, motherboards that support 4th Generation processors do not have AVX offset adjustmets.

    Download Prime95 and run only Small FFT's for just 10 minutes.

    • Prime95 v26.6 - http://www.mersenneforum.org/showthread.php?t=15504

    You might want to read this: Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html

    CT :sol:


    Howdy,

    I ran Prime95 with the version you listed & after 10 minutes it doesn't go higher than 67c.
    I'd imagine that these are "good" temperatures for a stock I7 4790k?

    Thanks,
    Mike
  6. Yes that temp is much better and will give you a bit of headroom for overclocking.
  7. DutchMike,

    Your Core temperatures are good.

    Here's the operating range for Core temperature:

    Core temperatures above 85°C aren't recommended.

    Core temperatures below 80°C are preferred.

    http://imgur.com/Svr2si8.jpgCore temperatures increase and decrease with Ambient temperature.

    CT :sol:
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