Considering a lower voltage?
Considering a lower voltage?
Hello,
I’m using an I9-9900KS and notice my temperatures are consistently high during gaming, with big fluctuations that bother me. When idle or under light load, I’m between 32-46°C, but it swings up and down a lot. During games, I can reach as high as 90°C, which seems unusual.
I’ve checked to make sure there’s no plastic cover on the cooler and replaced the thermal paste with Thermal Grizzly Kryonaut, making sure it was applied evenly. All fan and CPU settings are at their maximum levels. My MOBO is updated to BIOS version F9c.
I’m wondering if anyone has experienced a similar problem and found a solution. How should I proceed with underclocking my CPU? Everything seems fine except for XMP, where the CPU voltage fluctuates between 1.34x and 1.37x depending on the workload. Should I stick to a standard overclocking guide but lower the voltage instead of increasing clock speed to test stability?
I tried prime95 without AVX and reached 100°C in under 5 minutes.
Here are my system details:
- MOBO: Z390 Aorus Xtreme
- CPU: i9-9900KS
- Cooler: NZXT X72 Kraken
- RAM: 32 GB (3600 mHZ) Corsair Vengeance RGB PRO
- PSU: HX1000i
- GPU: Aorus 2080 Ti xtreme
- Case: NZXT H710i
- Radiator: mounted top as an exhaust, 3 front intake fans and 1 rear exhaust fan.
No, because 100C is the critical temp on that cpu. It would've forced a shut down had you continued with your testing.
It seems the radiator is functioning properly.
I think the problem might be with the motherboard - specifically the auto settings.
This particular board doesn't meet Intel's TDP requirements and is providing much more voltage than necessary.
Your CPU is essentially a carefully selected example of the 9900K; it should handle 5.0ghz at lower voltages than before.
If that makes sense, then your...
If you haven't checked yet, you might want to compare the VCCIO voltage with VCCSA (System Agent) voltage, as the BIOS XMP setting tends to push these numbers a bit higher during auto.
I own a standard i9 9900K and an AIO 280mm cooler (fans capped at 750 RPM), and I adjusted IO and SA from auto values of 1.328v and 1.264v to manual settings of 1.100v and 1.150v. This reduced the Prime95 AVX Small FFT temperatures by roughly 4 to 5 degrees Celsius.
After about 20 minutes of P95 Small FFTs using AVX, my CPU package reached 79°C, with one core reaching 81°C at a certain point. The additional 300MHz across all cores adds up to higher heat, which is noticeable.
I haven't tested with the fans spinning faster, as the noise bothers me, and I aimed for realistic temperatures for daily use.
It's not significant, but it's an improvement over nothing, and it helps avoid using excessive voltages unnecessarily.
However, I have no certainty about how much better the 9900KS will perform with the higher 300MHz all-core speed.
My RAM is at 3333MHz with average timings, so you might need a bit more IO and SA voltage if you go to 3600MHz—testing a bit would be wise.
It could also help to reduce the Auto Vcore slightly, though I don't have direct experience with the KS model, so I can't give an exact figure.
You might also consider using an AVX negative offset value, which allows the CPU to downclock when handling AVX tasks.
EDIT: Generally, you won't encounter Prime95 AVX workloads in regular use, so focus less on that. It's usually better to disable AVX during P95 runs.
But 90°C during gaming feels quite high (depending on the game), such as with Battlefield V, which uses AVX and tends to run hotter than many others.)
Thanks for your reply dude.
I'll check it when I get home. Would it make more sense to gradually lower my vcore at a higher interval first, like starting at 1.3v and then going down to 1.295 if everything holds?
It gets to 87c on Call of Duty: Modern Warfare, which seems a bit extreme to me! I’m sure I’ll never reach Prime95 in terms of workloads, but my OCD takes over and it doesn’t feel right.
Another user (on this forum with a custom loop) got 25c idle and 70c at max load. Mine would be hotter since I don’t have a custom loop, but you’d probably assume 90-95c during full load.
I previously progressed through upgrades until the CPU overheated or became unstable.
However, since you're aiming to lower the voltage and focus on stability, your approach seems logical.
I recall seeing a solid stable Vcore for the i9 9900KS at stock speeds, which would serve as a useful reference point.
I understand that not all chips perform identically, and direct comparisons aren't feasible, but the KS are considered top-tier, making such a comparison worthwhile.
I think the posted Vcore value was around 1.28, though I'm not certain.
Regarding temperatures, I remain uneasy when the CPU exceeds about 70°C—though that level isn't inherently dangerous.
I've configured the system to reach up to 69°C unless stress testing is involved.
Even the standard 9900K is quite hot, and the 9900KS even more so.
You'll likely need to adapt to tolerating higher temperatures than you're used to, but running it at stock settings with a 360mm AIO should still be feasible.
I tested my 9900K at a full 5.0GHz to check performance, and I managed the heat even with a 280mm AIO.
I'm reverting to stock settings again, as it was enjoyable for benchmarking, but I don't require such high clocks every day and found the temperatures unsatisfactory.
My values are as follows: if you're using stock clocks or a slight overclock, these are good starting points. I have four dimms; with only two available, you can likely lower VCCSA to 1.15v. VCCIO is set at 1.1v, VCCSA at 1.2v, and the fixed core voltage is 1.25v. I also adjusted Vcore, but the Vcore reading isn't showing in hwinfo, so I'll update here when I check again in BIOS. Please note I own a 9900k, not 9900ks.
I would suggest you use adaptive voltage instead of fixed (override), it will help lower the idle temp - there's no reason to have it sit at max vcore setting when idle or under light loads - the idea was to reduce operating temperatures.
You are not pushing a massive overclock to the limit, your CPU is confirmed stable and designed to operate with a vcore that increase or decrease with the workload. As far as I understand you just want it running at lower temps as an everyday desktop PC as close as possible to the default Intel voltages, not for pushing the CPU beyond its limit.
You generally can't compare the needed Vcore for a K-model at 5 GHz all-core 1:1, as a KS-model will reach that frequency at lower voltages due to the higher silicon quality / top binning.
But it is probably a good starting point.
Sorry, it seems you're asking about adjusting settings for adaptability. Could you clarify what you mean by "adaptive"?
I'm sorry, I don't have knowledge about Gigabyte's BIOS/UEFI. It seems there might be some confusion regarding the names and settings. Make sure to verify the correct information before proceeding.