Is there a need to undervolt my CPU?

[rbogomolec]

I've been playing around with this undervolting and so far I'm on -0.60mV. I read that my type of cpu (i7 4720hq) is usally between -0.60 and -0.100). So far I'm not sure if there is a drop in CPU temperature, maybe 2'C at most. So this raised two qestions for me:

1. Does undervolting only help if you're gaming on temperatures around 90'C? Some people said they got from over 90'C to around 80'C. I, however, never play on settings that make my CPU go over 75'C. Does it make any sense for me undervolting my CPU then? Do I have a chance of getting let's say -5'C or is my temp too low to begin with?

2. People say "lower your voltage by -0.10mV, stress test your CPU for a while and see if it crashes". But since I never really put my CPU under heavy load where it would start to throttle, I was wondering if I really need to stress test it. Let's say I put my voltage to -0.120mV and everything works fine, even my rise of the tomb raider game with my medium settings and 1280x720 resolution, which are the settings I have because I don't want to stress my CPU any harder. If I run a heavy stress test software however, everything crashes. Now, would this voltage be alright for me to use or no, since I'm not planning on stressing my CPU that hard ever again?

 

[winks42]

Always stress test the cpu after overclocking or under powering. This checks stability and makes sure you CPU doesn’t crash in game under load. If you think your temps are fine >74 then you don’t have to under power

 

[Karadjgne]

Cpus are made from silicon. Because of impurities in that silicon, every cpu is different. So one cpu might be stable at 1.16v, an identical cpu might require 1.224v. However, intel/amd has absolutely no idea what any single cpu will require for stability, so they bump vcore high, to maybe 1.25v and that covers all those cpus, guaranteeing stability across every cpu.

What you do by undervolting is look for your actual cpus stability requirement. With voltage use corresponding to heat output, the lower you can get the cpu, the lower the temps. But it's a fine line finding that limit, so yes, you must stability test after every drop.

I recommend Asus RealBench for stability testing. It's got nothing to do with temps. With every drop in voltage, run RealBench for an hour, and keep dropping the voltage in small increments until you get BSOD. Once that happens, bump the vcore back up 1 notch, then run RealBench for 8hrs. If it passes, you've found the lowest voltage required to run that cpu. If it fails, bump up another notch and test again.

Stress testing is looking for a baseline temp, checking to see if the cooling is enough, normally used with overclocking. It's not really required when dropping voltages as max temps will go down with every drop in voltage.

Regardless of actual temp, low voltage limit will decide your cpu temp, don't aim for temp lowering by sacrificing stability.