9900K Runs HOT!

JCNiest5

2[H]4U
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Apr 25, 2005
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Okay, I'm using a Corsair H100i V2 and my 9900K is idling at 48 C - 50 C, and goes way up past 100 C when Prime95'd. I don't believe it's inadequate thermal paste, but something else. I use Artic Cooling MX-4 thermal paste. What to check?
 
What's your ambient temperatures? Is the cooler seated properly? What fans are you running?
 
Pump failing? If you've checked that it's seated properly that's all I can think. Idle should be in the 20-30s.
 
Okay, I'm using a Corsair H100i V2 and my 9900K is idling at 48 C - 50 C, and goes way up past 100 C when Prime95'd. I don't believe it's inadequate thermal paste, but something else. I use Artic Cooling MX-4 thermal paste. What to check?

H100 won't cut it for that cpu, especially if you're tossing prime 95 at it. I built a custom loop for mine.
 
Stock fans that came with the H100i. The four thumb screws are all tight evenly, I have to believe it's seated properly. The fans all rev up, don't know how to confirm if the pump is at full speed. I can feel the air getting warm. I just think the 9900K just runs hot. Maybe need a better, different AIO cooler?
 
48C is still way too toasty for idle. Check my sig I idle around 32C. My room temperature is about 21C.
 
Stock fans that came with the H100i. The four thumb screws are all tight evenly, I have to believe it's seated properly. The fans all rev up, don't know how to confirm if the pump is at full speed. I can feel the air getting warm. I just think the 9900K just runs hot. Maybe need a better, different AIO cooler?
plug the single wire fan speed plug into a fan header to get the rpm. thumb screws should be as tight as you can get them by hand. double check your mounting. yes you might need better cooling.
 
48C is still way too toasty for idle. Check my sig I idle around 32C. My room temperature is about 21C.

It's winter here in MN. Not sure what else to do except getting a better cooler. What do you recommend?

plug the single wire fan speed plug into a fan header to get the rpm. thumb screws should be as tight as you can get them by hand. double check your mounting. yes you might need better cooling.

I'll double everything. Maybe I will try Artic Silver 5 and see if it makes any difference.
 
I recommend using Grizzly Kryonaut it's what I use. Also my set-up is a push/pull one.
 
Probably just didn't mount it evenly. I'd pull the cooler off and try again with a fresh paste. You can confirm the paste job then too as to whether it was bad or not.
 
I took the heatsink off, thermal paste was evenly spreaded across the IHS. Anyway, I tried Artic MX-2 this time. Now idling at 40 C to 43 C. So, better result. Still, not as good as reported elsewhere (or in here). Better AIO cooler is the next step?
 
Case is a Thermaltake Levl 10 GT White Snow Edition, but it's open. The board is a Gigabyte AORUS Z390 Pro Wifi.
 
I took the heatsink off, thermal paste was evenly spreaded across the IHS. Anyway, I tried Artic MX-2 this time. Now idling at 40 C to 43 C. So, better result. Still, not as good as reported elsewhere (or in here). Better AIO cooler is the next step?

A 240mm AIO should be sufficient at stock speeds. Getting shafted on the silicon lottery is not out of the question as was the case with Admiral Equinox in his first 9900k.

Compare the minimium voltages needed for stability on less demanding test like Cinebench to see if this is the case.
 
I got high temps on my X370 motherboard because the default fan speed (& voltage fed to the pin header) for the pump was quiet or low I think. Try checking your mobo bios for fan voltage or speed setting. Set it to max if you can to see if that helps.
 
Check if you have MCE (Multi Core Enhancement) on.

The new versions of Prime95 uses AVX so of course its gonna get toasty.

If going from 48-50C to 40-43C just from MX-4 to MX-2 then theres probably some mounting issues, maybe its not on tight enough or do a proper criss-cross when tightening.
 
Is that at stock voltage or are you overclocking

These 9900k's remind me of the old gtx 480's I ran in tri-sli.

You could warm your house with it if you are overclocking.
 
don't use prime 95. I have used AIDA64 and Realbench and my system is rock solid at 5ghz. It stays in the 70s with thermaltake ring flow 360. Now these use AVX as well. But fire up prime95 those avx instrcutions 95c instantly lol. I am not sure what they run, but it really is designed for max heat it seems. I am used to realbench and aida 64 and they have never failed me in diagnosing stability. But new prime 95 just feels like its desinged to toast your cpu then anything.

Also check voltages your idle seems high. mine is in the 30s. But either way prime 95 is going to set it on fire pretty quick.
 
Is that at stock voltage or are you overclocking

These 9900k's remind me of the old gtx 480's I ran in tri-sli.

You could warm your house with it if you are overclocking.

Stock speed. No OCing, but CPU Multi-Core Enhancement is Enabled. Pump RPM seems to be going around 800 in the BIOS. CPU VCore is around 1.236v something.
 
Check for air bubbles in the caught in the pump.. I had this problem when I ran my h100i a couple times after moving my pc. All I had to do was gently tap the water lines and rotate the case little. Easy to detect, one hose will be warmer than the other.
 
No go. I set the fan to 100% and it's still hot as the sun. Not sure what else to try other than getting a different cooler.

Using AIDA64 Stability Test and the temp also went the through the roof! I had to stop the test within a few seconds because temp went above 100 C.
 
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No go. I set the fan to 100% and it's still hot as the sun. Not sure what else to try other than getting a different cooler.

Using AIDA64 Stability Test and the temp also went the through the roof! I had to stop the test within a few seconds because temp went above 100 C.
you need to get the pump moving properly. try another header and use bios or speedfan or something to make sure you got the right one and then set it to max.
 
This. Get the pump moving MUCH faster.

Pump could be defective, but in any case check that all wires are connected correctly, when I installed my AIO on my CPU a couple weeks ago I messed one connection up which made 1 fan run full tilt and the other did barely anything, checking the connections was a quick fix.
 
Make sure you are using a header that gives pump enough power and is running at full speed, ideally a 1.5A or better one. Often on dual-type headers there is a bios setting to select PWM vs Full-DC/Pump/WC modes. AIO Pumps should be full speed all the time anyways because they are usually underpowered wimpy things, dial in your profile with fan control instead.

On my (now yanked) shittermax TR coolers the reported rpn difference between the fan header in right mode and not was 3000 vs 1800.
 
The pump should be moving much quicker. Install the h100i software and get it chooching. When the h100i fails you will know. Pump output shaft wears through the bushing and the pump eventually seizes. You get a lot of warning when the pump starts to shine.
 
For comparative I just picked up a 9900k as well, but using a H110i GTX, during my testing at stock to get baseline stability I'm sitting at about 31-33c on average in 74f (23c) ambient and it drops as low as 26c with it on 1.25v (it could likely go lower but I'm not aiming for stock).

Something to note, my OC Bot recommendation greatly increased by pulling the latest BIOS (4.9ghz max to about 5.2ghz max), something to consider.
 
Getting a new case, a darkForce I5 Phantom and a Corsair H115i RGB Platinum and will put them together and see how it goes. Got a CoolerMaster MasterBox MB500 TUF Alliance, but it's way too small. The front mounting area, supposedly can take a 240MM radiator, but I couldn't even install my H100i V2 on it without doing some clean up.
 
Getting a new case, a darkForce I5 Phantom and a Corsair H115i RGB Platinum and will put them together and see how it goes. Got a CoolerMaster MasterBox MB500 TUF Alliance, but it's way too small. The front mounting area, supposedly can take a 240MM radiator, but I couldn't even install my H100i V2 on it without doing some clean up.

When I built my 9900k setup, I used the almost 7 year old H100 (the original version of it) from my old PC on it. I had the 9900k at stock to start with. At first it seemed decent - idle temps were around 31-34c. Then I went to my go-to stress testing tool, Prime95. I was shocked when the temps blew through the thermal throttling limit almost instantly. I thought for sure the pump wasn't seated right or I didn't apply the thermal paste (using MX-4) evenly. I tried again and was 100% positive it was mounted perfectly, but there was no change to temps.

I thought maybe enough of the coolant may have evaporated out of my H100 being as old as it was (I've heard this is an issue over long periods of time with AIOs.) I then picked up an H115i and tried that. Idle temps were definitely better (down to 26-28c) and P95 testing brought it up to 78c or so. Still really hot compared to what I was used to, but obviously a HUGE difference from the old H100. Btw, when I installed the H115i, I just used the thermal paste it comes with pre-applied to the plate (and cleaned off the old stuff from the CPU, of course.)

The main thing that was a real learning experience for me was testing with Prime95 with the 9900k vs my previous CPU, a 3570k. Basically Prime95 is fucking insane with how it's set up. Between heavy AVX usage and massive voltage request, at 5.0ghz it still blows through thermal throttle limits after only a few seconds. I'm finding that other tools like Cinebench and Realbench are more realistic. Where P95 would throttle my CPU within 15 seconds, the other tests show a max of around 85c.

Any way you slice it though, the 9900k is just obscenely hot. It's a challenge for any cooler at stock clocks, let alone overclocked.
 
I took the heatsink off, thermal paste was evenly spreaded across the IHS. Anyway, I tried Artic MX-2 this time. Now idling at 40 C to 43 C. So, better result. Still, not as good as reported elsewhere (or in here). Better AIO cooler is the next step?
MX-2 cures quicker than MX-4, but other than that the MX-4 is the better paste. You probably just mounted the pump better this time.
Stock speed. No OCing, but CPU Multi-Core Enhancement is Enabled. Pump RPM seems to be going around 800 in the BIOS. CPU VCore is around 1.236v something.
Pump sounds like the culprit, as others said. Let us know how the H115i does.
 
Hi friend.
Rig in my sig is my second 9900k. My first 9900k was RMA'd because of similar issues with temps like yours.
I bought it specifically to get it to 5ghz, but it was just so fucking hot. At idle I was at 49-50c. Bewildered really, didn't seem right.
Didn't want to settle for that so packed it up for #2.

Here are the temps on my second 9900k @ 5ghz just doing desktop shit at 1.34v
https://imgur.com/a/jvdeSEy

Night and day difference. Using Thermal Grizzly Kryonaut.
Here's a pic of my rig if you want an idea of cooling.
https://imgur.com/a/hkgumgw

Nice choice on the h115i Platinum, this is a fantastic cooler.
 
Hi friend.
Rig in my sig is my second 9900k. My first 9900k was RMA'd because of similar issues with temps like yours.
I bought it specifically to get it to 5ghz, but it was just so fucking hot. At idle I was at 49-50c. Bewildered really, didn't seem right.
Didn't want to settle for that so packed it up for #2.

Here are the temps on my second 9900k @ 5ghz just doing desktop shit at 1.34v
https://imgur.com/a/jvdeSEy

Night and day difference. Using Thermal Grizzly Kryonaut.
Here's a pic of my rig if you want an idea of cooling.
https://imgur.com/a/hkgumgw

Nice choice on the h115i Platinum, this is a fantastic cooler.

Your temps are pretty low from what Ive seen. NICE!!
 
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