Water cooled 9900k rig: Overclock report

in STEMGeekslast month (edited)

For the last week I have been tinkering with the CPU settings of my new processor. Finding its limits with the new water cooling system. And finding the voltage limits of the motherboard, mostly the voltage regulator module. Using basic utilities like HWinfo64, Prime95, CPU-Z and AI Suite I was able to raise the processor speed from 4.6ghz on all cores to 4.9ghz on all cores. With the CPU getting into the 80s Celsius and the VRM into the 90s Celsius I do not think I will get much more from this 9900k CPU. That overclock puts it in the mid range of what can be expected from these Intel processors.

Some info on the tools I am using:

HWinfo64: This utility allows me to monitor voltages, throttling of the processor, temperatures and more.

Prime95: A stress testing tool that has the CPU compute very difficult calculations, these tests greatly stress the CPU making it heat up alot and keeping it busy. I tend to run this test overnight, anything shorter seems to not effective in testing for stability.

CPU-Z: A tool similar to HWinfo64 but has an easy to read interface making for faster troubleshooting in some cases.


I started off doing a short stress test at stock voltages and speeds to make sure my platform is well running with no changes. After that was complete I bumped up the voltage close to the limit of the suggested range.. Less than 1.5v to see what kind of temps I will be encountering, the most I could clock was 4.9ghz with a very high voltage, though I bumped the voltage down a few notches when I was familiar with the heat being produced.

Eventually I brought the CPU voltage down to 1.3ish volts as I found stability at lower voltages. Though the AVX tests were causing the tests to fail. AVX is an extension to the processor that some applications use, such as Adobe Premiere, 7zip and others. AVX processes tend to stress the CPU more than usual and this requires the processor to run at a lower clock speed so not to overheat or push the voltage regulator too hard.

https://en.wikipedia.org/wiki/Advanced_Vector_Extensions
Link about AVX

Above is a screenshot from HWinfo64 showing the CPU performance was limited due to the voltage getting too high. As I stated in my previous post on this build my motherboard is the weak link in this build.

I backed off the CPU clockspeed to just around 3.8ghz for AVX extension work. That is a 200mhz increase over stock, not bad. I may be able to push this further but for now I am okay with this as my gaming is not using AVX and having a higher non-AVX overclock is more important to me. After stress testing for 10 plus hours I find stability using 1.35v at 3.8ghz for AVX.

Noticed I was getting some limiting from the voltage regulator, but watching the CPU clock speeds it does not seem to be pulling back power. Like I said this motherboard is pretty basic and probably does not like the overclocking. CPU temps get up to 86F so I really dont want to push it much further.

Discovering my non-AVX voltage was up next.. I really wanted over 5ghz, as thats a nice number to settle on. But that was not the fate of this binned CPU. And not wanting to push more heat and more voltage into it I settled at 4.9ghz for non-AVX. That is a 300mhz overclock from the stock turbo speeds of 4.6ghz.

My hashrate has increased since the overclock, going from around 55kH to around 61kH. My old CPU got around 30kH so alot more processing power in this new rig.

A screenshot of my stable settings, VR voltage is my only concern, but I do not see the VRM temps going over 95F when Priming and rarely over 85F when doing any kind of real world computing.

Some initial gaming tests show a large increase in FPS, S.T.A.L.K.E.R can now be ran at max settings and kept over 30FPS, it mostly is around 60FPS which is great. Crysis remastered can be ran with "Can it run Crysis?" settings and stays in the 20 FPS or above range. Looking forward to trying Arma 3 as that game really hit my CPU hard. Though alot of these games do not make use of SLI, so I think my next upgrade will be replacing my two Nvidia 1080s with a single RTX 3090. Watching the GPU usage in S.T.A.L.K.E.R it is now maxing out my GPU so I probably need to upgrade. I also want to upgrade the RAM. Right now its running at 3000 mhz but the motherboard supports over 4000 mhz RAM. So I can see upgrading my video card and memory soon. And as I run out of disk space ill build a new RAID-10 array.

Great progress has been made on this machine, and a modest overclock was reached. Its made playing games more enjoyable, as my previous machines CPU was the bottleneck. But now with one of the best processors on the market I can really push my GPUs and RAM.

ZombieLoad logo

Enabling TSX extensions is my next project, it is currently disabled on this machine. Right now my BIOS is patched with microcode to block TSX. There is an exploit called ZombieLoad that uses TSX as its vector for attack. So newer CPUs such as the 10990k have it completely disabled. But previous generations like my 9900k only has it locked out through microcode. I think using some tools I will be able to enable this extension again. Or brick my motherboard.. lol one or the other probably.

This will allow for better parallelization of computing in the CPU, which will give my RPCS3 emulator for PS3 games a bump in performance and stability. Which is much needed for some games I want to play, and being aware of the exploit being possible is just something I will live with.

https://en.wikipedia.org/wiki/Transactional_Synchronization_Extensions
A link about TSX

Knowing this I will never store any valuable information on this machine, like private keys, passwords, or other important confidential details in the case my system indeed did get compromised. As any untrusted code could have a payload in it to exploits the TSX extensions again and I do plan on running alot of untrusted code doing gaming and modding and such. So its just something I will ever vigilant on.

A video showing how TSX being disabled vs enabled can change the FPS of the game when doing PS3 emulation
Source: ZEROx on Youtube

Looking forward to doing some console emulation on this rig, I have not had a chance to do too much yet. Just been running PC games on it to get a sense of the general increase in performance and checking for stability. But planning on returning to trying to emulate some of the most CPU intensive games like Red Dead Redemption, Forza Motorsport 7, Zelda Breath of the Wild and others. Hopefully they are all playable now with the increased power of my new CPU.

Link to previous post on this project:
https://peakd.com/hive-163521/@solominer/water-cooled-9900k-rig-building-a-new-pc