AIO or Aircooler

[Kaptain]

Hey guys, recently got back into pcs and have a build I'm fairly happy with, however my cpu often sits at around 70 - 80 degrees while gaming and when under a full load it'll spike pretty quickly to the high 90s before it throttles itself down.

I'm not sure if this seems normal in use cases but if it isn't I'd really like to get some on advice on what coolers I can have recommended.

I currently have a cooler master ML240L v2 and my case is a phantek P500a.

I'm considering going with 360mm rad or a noctua d15. But open to any other recommendations

Specs

9900k
Coolermaster ml240
Rx6800
32gig 3600mhz
750psu
Phantek P500A

 

[goldfritter]

9900k is a bit of a beast to cool... A few things:

• Did the cooler perform better in the past, or is this the way it has always been? If performance is deteriorating over time, consider cleaning dust out of the fans and radiator. Also consider reseating the cooler with new thermal paste.
• Where on the case is the cooler placed, and how are the fans oriented? The optimal position for CPU cooling is the radiator mounted on the front, with the fans oriented as intake fans, pushing air front-to-back through the radiator. The top part of the radiator should always be mounted higher than the CPU block - this is non-negotiable. Ideally also the tubes should be at the bottom of the rad, but that is less of an issue. Note that placing it this way means the air inside the case will be hotter for the GPU and other parts, but that is less of an issue usually than CPU thermal throttling.
• Can you adjust the speeds of the pump and of the fans? The header where the pump is connected should usually be at 100% all the time. The fans can be on a curve that responds to CPU temp. If you can increase the fan speeds then that can cool down the CPU better. But if they are at 100% already by the time the CPU hits 80deg then that won't help.
• Most motherboards tend to boost the 9900k's voltages quite high. Undervolting will make a difference. @affxct helped me tweak a 9900kf to the point where it stayed under 90deg with a 120mm AIO even under very heavy CPU workloads. I will post that info in the next reply.

Lastly, an NH-D15 might be a bit better than a 240mm AIO, but for a big upgrade to cooling, a 360mm AIO will be better. That said, with the above steps in mind, you should be able to avoid throttling even while using a 240mm AIO.

 

[goldfritter]

Here were @affxct's suggestions last time:

"I would go to the advanced CPU settings and disable the variable core ratios, as in allow the CPU to boost to all core. I'd disable MCE. I'd suggest dropping VCCSA and VCCIO to 1.05V and 1V respectively as they can both increase heat output and are only useful when you're trying to stabilize heavily OC'd RAM.

I'd attempt 4.8GHz all core with a base clock of 1.25V, I'd recommend setting a fixed voltage because it seems as though your chip like mine has a high VID propensity. VID by the way is what the CPU wants and not necessarily what it needs to be stable. 4.8 at 1.25 is low though so may 1.26V is a good start. I'd then go to the LLC settings and set LLC to Level 6. I'd then ask you to download HWINFO64 and make sure that while rendering the Vcore drops from 1.25V down to say 1.22V.

You may also want to stress test the underclock but those should be all the settings you'd need to adjust. This will not harm the CPU, not even if the PC BSODs. A BSOD simply indicates that there is some level of undershoot or lack of voltage hindering the PCs clock cycles across either the CPU, RAM, or both. But please keep in mind you need to stress test the CPU via IBT, Prime95 or ASUS Realbench and you absolutely cannot leave LLC on stock because it will undershoot. I think Level 6 should do it.

As a guide you basically want to see 4.8GHz @ 1.25V Level 6 LLC, no per core turbo, no AVX and no multicore enhancement. And you want to see that Vcore drop by approx 0.025-0.030V when you begin to render with the CPU. Those would be incredibly efficient settings."

-----------------------------------

And my response:

"Okay update, I did everything you suggested except I put core at 1.25V and the clock to 4.7. VCore in HWInfo dropped from 1.238 at idle to 1.210 under load with LLC 6. Temperatures went down by literally 20deg - averaging around 70 and spiking to 80. I set up OCCT to run for 8 hours, but unfortunately woke up to a BSOD this morning. So just to keep things stable while she works I set the core voltage to 1.29V. I know it's high but I don't want crashes and errors while it renders. Tonight I'll run another stress test at maybe 1.27V to see if I can get it stable.

There's no setting called MCE, but there is one called "enhanced turbo" or something like that and the tooltip description sounded like MCE to me so I disabled that. Might have got it wrong though.

So basically, dropping the voltage makes a huge difference to temps. I think I should be able to get things stable at a temp so she won't need to buy another cooler. Thanks again for all your help dude, I really appreciate it!"

-----------------------------------

And like I said - this is with a 120mm AIO (Corsair H60), front-intake mounted, so with your 240mm AIO you should be successful as well. This process caused exactly zero drop in CPU performance.

 

[Kaptain]

9900k is a bit of a beast to cool... A few things:

• Did the cooler perform better in the past, or is this the way it has always been? If performance is deteriorating over time, consider cleaning dust out of the fans and radiator. Also consider reseating the cooler with new thermal paste.
• Where on the case is the cooler placed, and how are the fans oriented? The optimal position for CPU cooling is the radiator mounted on the front, with the fans oriented as intake fans, pushing air front-to-back through the radiator. The top part of the radiator should always be mounted higher than the CPU block - this is non-negotiable. Ideally also the tubes should be at the bottom of the rad, but that is less of an issue. Note that placing it this way means the air inside the case will be hotter for the GPU and other parts, but that is less of an issue usually than CPU thermal throttling.
• Can you adjust the speeds of the pump and of the fans? The header where the pump is connected should usually be at 100% all the time. The fans can be on a curve that responds to CPU temp. If you can increase the fan speeds then that can cool down the CPU better. But if they are at 100% already by the time the CPU hits 80deg then that won't help.
• Most motherboards tend to boost the 9900k's voltages quite high. Undervolting will make a difference. @affxct helped me tweak a 9900kf to the point where it stayed under 90deg with a 120mm AIO even under very heavy CPU workloads. I will post that info in the next reply.

Lastly, an NH-D15 might be a bit better than a 240mm AIO, but for a big upgrade to cooling, a 360mm AIO will be better. That said, with the above steps in mind, you should be able to avoid throttling even while using a 240mm AIO.

Thanks for all the tips man. My rad is mounted on the top of my case which Ives seen people advise is the best possible place to have it. My fans are behind the rad to push out air out of it and through the top of the case.

With regards to noticing the Temps change, after I was done putting together the pc there was about a 3x week gap between finishing the build and testing it because I was so busy with work.

I'm going to try cleaning out the thermal paste and reapplying it cause I'm guessing Iay have put too much the first time. The fans and rad is fairly clean.

I haven't tried anything like undervoltint yet but I will give it a go before consider a different cooler.

I'm definitely going to use the steps you've listed in your previous message. Thanks so much for the help man