My H100i cools better with no fans on it

Safetytrousers · 19 Jan 2017 at 18:49

After some build adjusting my H100i v2 went dead. My PC was thinking there was no fans in the CPU fan header. Sticking in a fan directly to the CPU fan header let the PC boot as normal.
I got the H100 to be recognized again by doing a CMOS clear with the jumper cap. But although it all came back the two H100 fans were not and have not been working.
Since they have not been working my temperatures, going by several different diagnostic indications, in stress test, gaming and desktop use are all 5 degrees cooler.
(67 degrees max after long GTAV session with 4.7Ghz clocked 4790k 1.33v, CPU reaching 88% use, previous highest reading 73 degrees, both quiet profile on Corsair Link)

What's the frequency Kenneth?

Hotwired · 19 Jan 2017 at 18:54

Got a picture or diagram of how its all set up?

Safetytrousers · 19 Jan 2017 at 19:00

Hotwired said:
Got a picture or diagram of how its all set up?

I have two fans in the front. One (120mm) is all the way to the top. It has an unimpeded path along the underside of the radiator (mounted on the underside of the case roof), and there is an exhaust fan at the back at the end of the flow. The case has quite big holes all along the top. It's a Corsair 460x (non-RGB).
The change I made was moving one fan mounted on top of the case inside, the other fan remains on top (I can't get two inside because the RAM gets in the way). The radiator fans had been on top drawing air down on to the heat sink.
I can imagine that the cross-ways air flow is perhaps all the heat sink needs, but what seems weird is that the radiator fans not working has better than no affect.

On a tangent I have a 140mm unimpeded fan blowing across my GTX 1080FTW (a third above and two thirds below and blowing right down its slits) and gaming life has never been so good.
Death to optical drive and drive cages.

Hotwired · 19 Jan 2017 at 19:36

Airflow and noise is related to how fast the fan is allowed to spin, on quiet settings airflow can be quite pathetic. Could be that they were spinning just enough to negatively affect airflow through the radiator.

A rad on the roof naturally the heated air wants to rise and get out, your fans were working against that.

Interesting that you have a fan outside the case, I've seen a pic of that case with a double radiator and it seemed to fit fine on the front.

Safetytrousers · 19 Jan 2017 at 20:04

Hotwired said:
Interesting that you have a fan outside the case, I've seen a pic of that case with a double radiator and it seemed to fit fine on the front.

Yes, you can put a radiator in the front, and a longer one at that. But doing that would mean I couldn't have a fan blowing fresh air so directly at the GPU.

Hotwired · 19 Jan 2017 at 20:23

Fair enough.

If the airflow you have is sufficient for you then I'd take off the radiator fans.

If you fancy having them back on again I'd have them blowing upwards.