Junior Member
Jun 23, 2020
I have a gaming build which is close to four years old now (built it in 2016).

CPU - Intel i7 6700k @ 4GHz. Turbo upto 4.2 GHz (no overclocking)
GPU - Zotac GTX 970 (no overclocking)
CPU Cooler - H100i GTX
Motherboard - Asus E3 Pro Gaming v5
BIOS version - 2606
Case - Corsair C70 Vengeance (lots of openings for airflow)
Fans - 5 [2 intake and 3 (2 AIO radiator+1 rear) for exhaust ]

Of late, I observed quite high idle temps on my CPU (close to 60c with random spikes up to 85c), while gaming (Arkham Knight, GTA V, Alien Isolation) it would shoot up to 90c and occasionally hit 100c (never had an automatic shut down though).
I hadn't replaced the stock thermal paste which came with the H100i GTX in all these years. So the first thing I did was replace the stock thermal paste with the Arctic MX-4 2019 edition and for good measure cleaned out the case, air filters, fans and the radiator fins. I even replaced the stock thermal paste on the GPU with the Arctic.

Although my idle temps have come down from 60c to hovering around the 45c-50c mark (I think this is high for idle), I can still see spikes of up to 85c.

Playing Batman Arkham Knight on Ultra ( with PhysX turned on) yields sustained temps of 85c-87c with spikes of up to 100c on the CPU and the GPU stays close to 80c but never exceeds it. Running even a simple stress test such as the CPU-Z bench for 10 mins gives sustained temps of 95c-100c at 100% load. I didn't bother with Prime95. Motherboard temp is at 41c. I live in India where the climate is warm. The ambient temperature is usually around 30c in the monsoons and can even hit 40c in summers (I have an air conditioner in the room but I don't run it all day long). Could this be a contributing factor?

At first, I thought I had botched the thermal paste application but since then I have cleaned and re-applied the same (dot method) at least 6 times with the same high temps. The cooler pump is working fine and so are all the fans.

I am at my wits end as to how to proceed with this. I have ordered the Noctua NT-H1 as a back-up because the Arctic is only good for two-three more applications.

I would like to hear some suggestions from you guys.
Does the i7-6700K usually run at high temps?
Is the Arctic MX-4 any good or should I use the Noctua NT-H1?
Should I opt for air cooling (Noctua NH D15) instead of AIO? (getting the CPU block to mount is a bitch due to the thick tubes)

P.S. I know, too many questions. Apologies!


Golden Member
Nov 6, 2009
I used to test coolers on an i7 4790k and an i7 8700k (the latter at 5 GHz) on Linpack w/ AVX2, so it was more stressful than gaming.

High-end heatsinks (air coolers) ran in the low 80's, spiking (from Linpack) to mid-90's. The only difference I can see is that my ambient was around 20c while yours is 30-40c. Still, I think you have a problem. It is over my head to help you troubleshoot, but I hope this confirmation helps.


Elite Member
Super Moderator
May 4, 2000
Could the liquid in the AIO be going bad/not effective/clogged after 4+ years? You also say you have high ambient temperatures (up to 40c, or 104F, so of course that plays a factor in temps).

I'd try to use an air cooler on it, and if the temps are better, you likely have your answer.
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Junior Member
Jun 23, 2020
Hey, guys! A small update after more than two weeks of the original post. I changed the thermal paste to the Noctua NT-H1,

It's been a week since I've applied the H1 and I'm seeing marginally better temps, although, I wouldn't say they're 'great'. Idle temps are now in the 35c-40c range and gaming temps lie somewhere in the high 70s (celsius). At least I'm not getting spikes that touch 100c, for now.

After going through the replies I really think that something's not right with my cooler. It could be any number of reasons you guys listed and I've decided to change my cooler in the near future.

Thank you, amazing folks, for the prompt replies and suggestions! You guys are the best!