What are safe temps for 8700k?

Basically got a 8700k with a 240mm aio. Maybe I’m old school, but I typically think like above 80C should be avoided. I am exceeding that in stress tests even at stock voltage and clock. I see some places claiming, like up to 100C or maybe even 105C is OK. I don’t want to destroy the life of my CPU, but i also don’t want to gimp my PC because I’m stuck at what max temps used to be. Like I see gamers nexus having their 8700k at 1.4V and 5Ghz in their recent benchmarks comparing the 2600k to new CPUs; figure he knows what he’s doing, so i set my V to 1.35 and 5Ghz, did a short benchmark(user benchmark) and two of my cores got to 98C!

105C is TJmax meaning it will downclock from there to keep the CPU from going into really dangerous territory.
Ok but not the most optimal temps are in the 80 - 90 range.
Ok temps are in the 70 - 80 range.
Optimal would be in 60 - 70 range.
Do note that stress tests make a worst case scenario so if you hit TJmax there then something may be wrong.

What are your temps with stock?

Check your thermal paste and also check if your CPU heatsink or CPU cooler is not slightly bowed. JayzTwoCents made some nice videos about that:


At about ~05:00

At about ~06:00
In both it was either the thermal paste or a slight bowing in the heatspreader/cooler.

AiOs seem to also have some pump failures here and there so check if it runs smoothly, I rarely use one so maybe check with your ear to hear if it seems that it’s struggling?

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In addition to what Hako said already, the 8700k is an inherently hot chip. The stock TIM intel uses isn’t that good and the core architecture is being pushed to its limits. Delidding the cpu does help a lot with temps but will definitely void the warranty. If you’re comfortable with that Gamers Nexus and Der8auer both have good vids on the procedure

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Its also weird in that it seems oddly dependent on which stress test I use. Like at 4.7Ghz on all cores, it will stay around 80C on Prime 95 until like the first round is complete then the cores suddenly spike to 90C. And then i Tried HeavyLoad as a stress test, and I don’t think any of the cores went above 70C, with all 12 cores at 100%.

This highly will depend on if the CPU cache is hit as well or not (and the iGPU, but this is less so). I believe the 2nd round of tests hit the CPU cache hard, and the 3rd round is maxing out power consumption iirc

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Anything below Tjunction, which is 100C, is safe.

Be aware that even if the temp is safe for your CPU, running your coolant above say 60-65C is probably out of spec for your AIO, and will kill your pump prematurely.

So… not sure if you have the ability to measure coolant temp, but i’d be trying to keep coolant temp below 60-65C, whatever the core temp is.

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Well prime95 is probablly the worst stress test for a cpu.
So if you see spikes to 90C doesnt really suprise me all that much.
You could also test with Asus realbench or OCCT.
Or a couple of Cinebench tests.

80C to 90C under prime95 is kinda normal i guess at those clockspeeds.
You could try to re-apply thermal paste, maybe that will shave a few degrees off.
But if all other stress tests dont go much over 70C and being perfectlly stable,
then i wouldnt worry about prime95’s temp numbers.

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