skutniewski92 :
... 4790K ... Within moments of starting up Prime95's small FFT's test, my CPU runs right to 99C ... Corsair H60 AIO ...
skutniewski92,
Which
version of Prime95?
There's an issue with Prime95 which is strictly
version dependent, and is a well known problem. Any versions
later than 26.6 will cause your 4790K to behave exactly as you've described due to AVX Instruction Sets.
From Intel:
Troubleshooting Intel® Core™ i7-4790K / i5-4690K overheating -
https://communities.intel.com/docs/DOC-23517
Also, 100% CPU utilization seldom equals 100% workload which means 100% TDP.
Intel tests their processors under carefully controlled conditions at 100% TDP.
Prime95 version 26.6 Small FFT's is ideal for CPU thermal testing, because it's a
steady 100% workload with
steady Core temperatures that typically runs Core i variants with Hyperthreading and Core 2 processors within +/- a few % of TDP. No other utility so closely replicates Intel's proprietary test conditions. This is also the utility that Real Temp uses to test Core temperature sensors.
Do
not use Prime95 versions
later than 26.6 on 2nd through 8th Generation i3, i5 or i7 CPU's, which all 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. The FPU test in the utility AIDA64 shows similar results.
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. AVX doesn't affect Core i 1st Generation, Core 2, Pentium or Celeron processors since they don't have AVX Instruction Sets.
Please download, then run
only Small FFT's for just 10 minutes.
• Prime95 v26.6 -
http://www.mersenneforum.org/showthread.php?t=15504
If you’re overclocked and run AVX apps such as for rendering or transcoding, you may need to reduce Vcore and Core speed or upgrade your cooler and case fans so Core temperatures don’t reach 85°C. Many 6th, 7th and 8th Generation motherboards address the AVX problem by providing offset adjustments in BIOS. An offset of -2 or -3 (200 or 300 MHz) is usually sufficient. Asus RealBench runs a realistic AVX workload typically within +/- a few % of TDP, and is an excellent utility for testing overall system stability, whether you're overclocked or not.
• Asus RealBench - http://rog.asus.com/rog-pro/realbench-v2-leaderboard/
Prime95's default test, Blend, is a fluctuating workload for testing memory stability, and Large FFT's combines CPU and memory tests. As such, Blend and Large FFT's both have fluctuating workloads which aren’t well suited for CPU thermal testing.
Other stability tests such as Linpack and Intel Burn Test have cycles that peak at 120% workload, which again aren’t well suited for CPU thermal testing. The test utility OCCT runs elements of Linpack and Prime95, which will terminate the CPU tests at 85°C.
The "Charts" in SpeedFan span 13 minutes, and show how each test creates different thermal signatures.
Shown above from left to right: Small FFT's, Blend, Linpack and Intel Burn Test.
Note the
steady thermal signature of Small FFT's, which allows accurate measurements of Core temperatures.
A steady 100% workload is crucial for thermal testing.
Shown above from left to right: Small FFT's, Intel Extreme Tuning Utility CPU Test, and AIDA64 CPU Test.
Intel Extreme Tuning Utility is also a fluctuating workload. Although AIDA64's CPU test is a steady workload, it's far below TDP, which is insufficient for thermal testing. All other AIDA64 CPU test combinations are fluctuating workloads, which again aren't well suited for thermal testing. Also, AIDA64 is not Freeware, so the Trial version expires.
Here's the operating range for Core temperature:
Core temperatures above 85°C aren't recommended.
Core temperatures increase and decrease with Ambient temperature. Idle temperatures below 25°C are generally due to Ambient temperatures below 22°C.
Also,
James Mason is correct; the Corsair H60 is only on par with mid-range air, so it's borderline inadequate for the 4790K.
If you'd like to get up to speed on this topic, then please read this Sticky:
Intel Temperature Guide -
http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html
CT
Facebook
Twitter
Instagram