CPU running hot on water

[jcdyben]

I have an i7 8700k overclocked to 5ghz on 1.304V, using a Corsair H100i v2 to cool it

While in games, it usually stays within 50-60 C, sometimes going up to 70 C which was fine, but recently I've started video editing and noticed the temps getting really spicy in the 90's. Decided to load Prime95 - instantly crashed when it began to stress test. System temporarily freezes for 10-60 seconds at a time while in blender as temps begin to go into the 90 C's. It seems my computer likes to shut down the second it reaches 95 C. I'm not sure what the issue is as a 240 mm AIO should be more than enough to cool it, and I understand it runs hot but most other people run the same specs at much lower temps, should I mess around with voltages to try and get a cooler chip? Does it sound more like my cooler is mounted wrong or not enough thermal compound is spread around? This computer was the first time I used A) watercooling and B) overclocking so I'm not sure if I just did something wrong too. Any help is appreciated

 

[RememberThe5th]

How old is it the H100i V2?

 

[dstln]

Yeah I think you're just pushing it too far. Video compression and prime95 use AVX, which increases the temp load dramatically. Pretty clear your system can't handle it with the voltage, and the H100i, while generally good, isn't like a professional foolproof solution.

 

[Pinhedd]

I have an i7 8700k overclocked to 5ghz on 1.304V, using a Corsair H100i v2 to cool it

While in games, it usually stays within 50-60 C, sometimes going up to 70 C which was fine, but recently I've started video editing and noticed the temps getting really spicy in the 90's. Decided to load Prime95 - instantly crashed when it began to stress test. System temporarily freezes for 10-60 seconds at a time while in blender as temps begin to go into the 90 C's. It seems my computer likes to shut down the second it reaches 95 C. I'm not sure what the issue is as a 240 mm AIO should be more than enough to cool it, and I understand it runs hot but most other people run the same specs at much lower temps, should I mess around with voltages to try and get a cooler chip? Does it sound more like my cooler is mounted wrong or not enough thermal compound is spread around? This computer was the first time I used A) watercooling and B) overclocking so I'm not sure if I just did something wrong too. Any help is appreciated

I'm moving this to the overclocking section.

It sounds to me like your cooler is either improperly installed, or your CPU is massively overvolted. It's well past my bedtime so I'll let someone else figure this one out.

 

[jcdyben]

How old is it the H100i V2?

Only around 8 months old

 

[Dunlop0078]

If prime95 crashes immediately your overclock is not stable. And I would use prime95 26.6 with that cpu it has no AVX instructions like newer version of prime, the older version is more relistic for a gaming pc.

It idles at 50-60c? Thats quite bad. Either your cooler is not installed properly, the pump is not working, or you have some messed up BIOS settings. I wouldn't think 1.3v vcore would cause temps like that, have you touched any other voltages?

 

[RememberThe5th]

Plug pump to cha_fan (3pin one) , the pump has to run 100% of time, plug fans into cpu_fan. (Just checking if you did)

 

[genz]

An 8700 on a H100 idling at 50C.

This is already an issue worth reporting in. With the temp spiking I would be tempted to ask you if you're absolutely sure that your Water Pump header on your cooler is permanently set to 100% in BIOS AND Corsair app. I'm 80% sure it's this, because there should not be a way for your CPU to reach 95C under a H100 period. Ever.

Assuming it's not, you want to down clock the AVX multiplier in your BIOS to 4 bins below your CPU base clock. Please understand AVX should NOT run at 'stock clock' according to Intel spec. AVX is not even 64 bit, it's 512bit VLIW and generates a LOT of heat as it's using that many bits by running 4 64 bit register banks or 8 32 bit ones and processing 4 or 8 numbers per clock, per core. That's up to 8 times the power draw per core, aka very hot. When you've confirmed your AVX throttle to be 400mhz below stock speed, test it again and see how blender or Adobe Renders are handled by it temp wise.

Honestly, it would be fair to say that someone took a look at the modern core, said 'how can we use that all at once' and AVX was born.

 

[jcdyben]

I decided to pop it open, and aha found the problem. I'm unsure how, as when I first installed it I made sure everything was correct and tightened properly, but the thumbscrews used to hold on the cooler had become insanely loose. I was able to wiggle around the cooler quite severely and I believe the temperature was do to poor contact between the cpu and cooler. I guess vibrations in my room (I'm right above my washer and dryer, so when they're going I can feel it in my room) may have loosened the screws, but anywho I retightened them and have normal temperatures. Still going to dial my overclock down to 4.9 ghz for safety and stability