Which prime 95 version should I use for i5 4670k?

ttreaders1,

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

At the top of all our Forums are "Stickies" which are informative Threads that are permanently "stuck" in place so they're always quickly accessible as reference material for everyone's benefit. Near the top of our CPUs Forum you'll see this Sticky:

• Intel Temperature Guide - http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html

You should give it a read. From the Guide:

" ... 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.

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

Note: 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 ...

... 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/

From Intel:

• Troubleshooting Intel® Core™ i7-4790K / i5-4690K overheating - https://communities.intel.com/docs/DOC-23517

• Intel Discusses i7 4790K Core Temperatures and Overclocking - https://www.youtube.com/watch?v=BGTnJkuqlbo

Once again, welcome aboard!

CT