High temps with Prime95 - i7-4790k with H100i GTX

[Niteshade]

Gear:
CPU: Intel Core i7-4790K 4,0GHz
CPU cooling: Corsair Hydro H100i GTX
Motherboard: ASUS Z97-A
Memory: Corsair Vengeance Pro DDR3 2400MHz 32GB 4x8GB CL11
Graphics: ASUS GeForce GTX 970 4GB STRIX DC2 OC
PSU: EVGA SuperNOVA G2 - 650W

Issue:
Downloaded Prime95 to stress test my CPU. Before turning on the mixed test I upped the H100iGTX Cooler Pump to Performance mode and the H100i GTX Cooler Fan to Fixed (%) using Corsair Link in order to make sure both ran at 100%.
The problem is that I got some worrying temps - The CPU temp basicly just climbed and climbed and once it reached 90C I shut off the tests to prevent the CPU from shutting down and rebooting. I also noticed in CPU-z that the multiplier got stuck at 42x (it goes all the way to 44x - or it should, which suggest thermal throttling if I am not mistaken).

Chassis, airflow and fan setup:
I have a Cooler Master Storm Scout II which I've case modded so that the H100i GTX is mounted in the front (yes, behind the panel) taking in air. It is powered by the two 120mm fans that was included with the H100i.
Other than that, I'm running with a positive air pressure using 6x 120mm fans placed like this:
Intake: 1x Bottom, 2x Side
Exhaust: 2x Top, 1x Back
So a total of 5x 120mm fans intake, and 3x 120mm fans exhaust, not counting the PSU.

Pump installation:
The pump was initially VERY lose when I first attached it to the CPU socket so I had to take it out and add double washers on the backside of the mobo. This made sure that when I screwed on the thumbscrews, the cooler/pump was stuck rock-solid to the CPU.
I used the thermal paste already attached to the H100i pump - I did not clean it away with acetone/alcohol to apply my own paste.

Idle stats
These are the RPMs and temperatures during idle in Windows...
Ambient temp: 22.4C
ST2000DL003-9C VT166 Drive Air Flow Temp: 30C (no idea what this is, but its listed by Corsair Link)
ST2000DL003-9C VT166 Drive Assembly Temp: 30C (same as above)
ASUSTeK Motherboard TZ00 Temp: 27.8C
ASUSTeK Motherboard CPU Temp: 29C
ASUSTeK Motherboard Mainboard Temp: 25C
ASUSTeK Motherboard CPU Aux Fan: 830 RPM
ASUSTeK Motherboard TZ01 Temp: 29.8C
Intel Core i7-4790K Temp: 26C
H100iGTX Cooler Pump: 1600-1700 RPM during quiet mode
H100iGTX Cooler Fans: 840 RPM during quiet mode
H100iGTX Cooler Temp: 27.2C
Chassis fans: 23.5C to 26C (in/out)

Also, GPU Temp @ 31C with no fans spinning (gcard has this 0db DirectCU-II cooler which only activates at 50% load or something)
and the SSD Assembly Temp @ 35C - so obviously good chassis temperatures.

So yeah, this doesn't really make sense to me. If the pump/cooler was poorly attached I would have poor idle temps and not just these crazy temps during stress testing.

And on a sidenode:
Is it just me or is the 120mm radiator fans on the H100i REALLY LOUD?

 

[caddi daddi]

yea, the corsair kits are loud.
are you at stock clocks?

 

[Niteshade]

yea, the corsair kits are loud.
are you at stock clocks?

Yes - I have not done any OCing.
Can you recommend some good (read: silent) 120mm fans that I can use on the radiator instead of the stock ones?

 

[caddi daddi]

you are reaching 90c at stock clocks, THAT is the first issue we need to work on, I am sure others will comment on fans.
do you have a connector you can power the pump with and go around the corsair lnk?

 

[caddi daddi]

ok, you say you are having to add some washers to the underside of the motherboard, to shim the backplate to get a tight mount?

 

[Niteshade]

you are reaching 90c at stock clocks, THAT is the first issue we need to work on, I am sure others will comment on fans.
do you have a connector you can power the pump with and go around the corsair lnk?

The H100i GTX has two cables to it that are stuck to the pump, and one optional mini-USB cable which you connect to an internal USB-header. The latter is used by Corsair Link.
The two cables comming from the pump: One goes into the CPU_FAN -header on the motherboard, and the other one powers the radiator fans. The LED, radiator and fans are all operational and I can control them via Corsair LINK.
But, I did experience problems when first booting up the PC - thread here: http://www.overclockers.com/forums/...g-issues-and-a-undetected-H100i-GTX-(new-rig)
That issue with the BSODs and freezing has been resolved (faulty PSU), but the issue with the mobo not understanding that the pump power is connected to CPU_FAN is remaining. I've currently turned off monitoring of said header in order to avoid CPU FAN ERROR during POST. I'm not sure if these issues are related, but I'm not ruling out that possibility.

I would also like to point out that the H100i GTX does NOT have a SATA-power connector. It appears that this was used in older versions of the H100i but was removed for future updates to the model. The current one gets it's power from the CPU_FAN header exclusively afaik.

Additionally, I would like to point out that HW Monitor detects the pump and appears to be listing it's RPM correctly.

EDIT: Running the latest BIOS update and the latest chipset drivers as well

 

[caddi daddi]

do you see pump speed in corsair link or other software and/or the bios?

 

[Mr.Scott]

Additionally, I would like to point out that HW Monitor detects the pump and appears to be listing it's RPM correctly.

You mean it's listing it the same as Corsair's software or the bios. You don't actually know whether it's correct or not.

 

[caddi daddi]

I suspect that you are using the wrong standoffs to mount the block.
look in the manual and you will see you have three sets of standoffs, I suspect you are using the socket 2011 standoffs, on these, one end is shorter than the other.
you need to be using the socket 115x standoffs, these are the same length on both ends and this is giving you a mounting issue.
the black standoffs are for amd.

 

[Niteshade]

I suspect that you are using the wrong standoffs to mount the block.
look in the manual and you will see you have three sets of standoffs, I suspect you are using the socket 2011 standoffs, on these, one end is shorter than the other.
you need to be using the socket 115x standoffs, these are the same length on both ends and this is giving you a mounting issue.
the black standoffs are for amd.

No I'm using the silver ones with equal-length -ends, which are for 11X0 -socket mobos: I followed the manual but still there was a lot of spacing between the thumb screws and the motherboard. Adding double washers on the back side of the mobo fixed this problem, as I was able to screw the hand screws tight (without screwdriver!).

I found an interesting thread about the current version of Prime95 and it's effect on Haswell -processors which might be to blame:

"NEVER EVER EVER EVEEEEEEEEEER use Prime 95 on a Haswell based CPU. Intel themselves made a program specifically for overclocking their Haswell CPUs because every other program overvolts the processors into oblivion. It can and will fry your CPU if used for an extended period of time. There's nothing wrong with your cooler nor your overclock, Prime 95 is solely to blame." -- Me1z
http://linustechtips.com/main/topic/342917-h100i-gtx-high-temps/

And:
"Ivy Bridge and Haswell are different chips and Prime95 actually overvolts the Haswell chips during the torture tests causing the thermal overload!" -- zxgravediggerxz
http://www.tomshardware.co.uk/answe...-runs-cpu-hot-confort-overclock-2ghz-25v.html

 

[Tech Tweaker]

What version of Prime95 are you running?

That overheating or over-volting problem only happens with some versions of the software. I believe it's related to running AVX instructions if I am remembering correctly.

 

[Niteshade]

Prime95 v28.5

 

[SuperDave1685]

Hmmmm..... interesting info about Prime95. I hadn't heard that before, but thanks. I use OCCT.

 

[Mephistohate]

No I'm using the silver ones with equal-length -ends, which are for 11X0 -socket mobos: I followed the manual but still there was a lot of spacing between the thumb screws and the motherboard. Adding double washers on the back side of the mobo fixed this problem, as I was able to screw the hand screws tight (without screwdriver!).

I found an interesting thread about the current version of Prime95 and it's effect on Haswell -processors which might be to blame:

"NEVER EVER EVER EVEEEEEEEEEER use Prime 95 on a Haswell based CPU. Intel themselves made a program specifically for overclocking their Haswell CPUs because every other program overvolts the processors into oblivion. It can and will fry your CPU if used for an extended period of time. There's nothing wrong with your cooler nor your overclock, Prime 95 is solely to blame." -- Me1z
http://linustechtips.com/main/topic/342917-h100i-gtx-high-temps/

And:
"Ivy Bridge and Haswell are different chips and Prime95 actually overvolts the Haswell chips during the torture tests causing the thermal overload!" -- zxgravediggerxz
http://www.tomshardware.co.uk/answe...-runs-cpu-hot-confort-overclock-2ghz-25v.html

The backplate of the H100i GTX is supposed to be loose, the thumbscrews tighten it up after you put the pump on, I have the same cooler and cpu (4790K) running at 4.4Ghz turbo boost, my idle temps are generally around 27-30C depending on the ambient temperature in my room, but with AIDA64 (I refuse to use Prime95 with Haswell) I get around 55C at 100% load, I use a custom fan setting in the corsair link software and the pump on quiet mode.