Core-i7 6700k High Idle Temp

Nikesh · December 10, 2018

Hi Everyone

Please can someone assist me with understanding why the idle temps on my 6700K is so high. Below is some info and background to the problem (all temps are in Celsius). Let me know if you need anything further. Thanks!

System is about 2 years old now
Ambient temp is approx. 24 degrees
CPU package idle temp is approx. 45 degree
I'm pretty sure it used to idle in the 30's when I first built the system
I recently migrated my system from a Corsair 760T chassis to a NZXT H440i but the temps were high even before that (so I'm sure that's not the issue)
I swapped the stock fans on the H115i cooler for Corsair ML140 Pro fans (unsure of effect on thermals)
I swapped the stock thermal paste for Cooler Master MasterGel Maker thermal paste (brought the temp down about 10 degrees)
H115i pump is set to quiet (should this be set to performance all the time?)
H115i fans are set on a custom fan curve linked to the temp of the liquid (liquid is currently sitting at 35 degrees)
CPU is not overclocked and voltages are set to default
I noticed that the CPU is constantly turbo-boosting to 4.2GHz even when I'm not doing anything (is that normal?)
GPU idles in the mid-to-high 40's (50 degrees max)
Weird thing is that when I run a game, the CPU temp doesn't spike too much, it rarely goes over 70 degrees (which I think is fine?)

System summary:

Intel Core-i7 6700K
Corsair H115i CPU cooler with Corsair ML140 Pro fans
NZXT H440i chassis with stock case fans
MSI Z170A Gaming Pro Carbon motherboard
Asus ROG GTX1070 Strix OC GPU

Cereal5 · December 10, 2018

39 minutes ago, Nikesh said:

CPU package idle temp is approx. 45 degree

My 8700K idles around 39-42 so I wouldn't worry about it too much. If your load temps are really high then I would, but idle temps don't mean much.

40 minutes ago, Nikesh said:

H115i fans are set on a custom fan curve linked to the temp of the liquid (liquid is currently sitting at 35 degrees)

IMO, better to run it off CPU temp. Probably doesn't matter a whole lot though.

41 minutes ago, Nikesh said:

I noticed that the CPU is constantly turbo-boosting to 4.2GHz even when I'm not doing anything (is that normal?)

That is the stock boost speed of the 6700K.

41 minutes ago, Nikesh said:

GPU idles in the mid-to-high 40's (50 degrees max)

See above.

41 minutes ago, Nikesh said:

Weird thing is that when I run a game, the CPU temp doesn't spike too much, it rarely goes over 70 degrees (which I think is fine?)

Do a load test in AIDA64 or Asus Realbench. If your temps are getting over 80C at stock speeds then your cooler is likely mounted too loose. If it's closer to 60 or 70C then I wouldn't worry about it. It's a little hot for a 280mm cooler.