Why does my CPU reduce its speed and voltage during stress tests?
Why does my CPU reduce its speed and voltage during stress tests?
During the stress test, the clock speed decreased from 5.0Ghz to 3.9–4.0Ghz. The temperatures ranged from 90˚C to 70°C, and the voltage shifted between approximately 1.400–1.550 and 1.250–1.300. I enabled CPU Over Temperature Protection at 100˚C and turned off the CPU Thermal Monitor, but this didn’t resolve the issue. I then adjusted voltages and settings—such as LLC—to lower temperatures. This allowed me to stress test the system and verify stability of the CPU. I lowered the CPU voltage from 1.500 to 1.370, adjusted VCCIO from 1.350 to 1.200, reduced CPU System Agent Voltage from 1.300 to 1.250, and changed LLC from Turbo to Medium. Despite these changes, I still observed reductions in clock speeds, voltages, and temperatures during tests with RealBench or Prime95. Benchmarks appeared normal, but the measured voltages were higher than those reported by HWMonitor. The voltage was set at 1.370V with an offset of 0.030+; however, it increased to 1.500–1.512V during stress tests before thermal throttling or other effects occurred.
It seems you're using a Ryzen chip with PBO activated. PBO can change BIOS parameters, so you should turn it off during overclocking.
Sorry. I didn't include the details about the equipment. Here are the specifications you mentioned:
CPU: Intel i7-11700K
GPU: Asus RTX 3060 12GB Rog Strix OC
RAM: G.Skill Ballistix 4x32GB (128GB)
PSU: Corsair RM850X 850W
Motherboard: Gigabyte Z590 UD AC
CPU Cooler: Noctua NH-D15
Drives: 3 x M.2 NVME Drives, 1 x SATA SSD Drive, 1 SATA HDD Drive
The processor may reduce performance because of overheating protection triggered by CPU throttling. Sudden changes in voltage or heat can lead to this behavior.
You're using an intel processor with standard configurations, but it handles very demanding tasks like AVX 512 stress tests for 56 seconds before automatically returning to the default 125W power limit. To maintain maximum performance continuously, you'll have to manually overclock the CPU.
I spent the entire day yesterday studying overclocking and attempting to boost my CPU, staying awake until 5 AM. I woke up at 9 AM today and continue working diligently on this. Since I’m facing real difficulties here, I really need any assistance possible at this stage! In the Turbo Power Limit section, there’s no choice to disable it for the Gigabyte BIOS, but should I set it to auto instead of the default POR setting? Check the current settings: https://imgur.com/a/oF7bfhp and view them here: https://imgur.com/a/09nuMde.
I lack significant understanding of Prime95 and chose not to explore it thoroughly since there’s a lot to cover. That’s why I’m relying on RealBench for stress testing. My attempt with Prime95 was to see if similar results would occur, and they did. Running it in Adobe After Effects or Media Encoder, or loading a game in Star Wars Battlefront II, doesn’t cause the same drop in performance. When these programs execute, temperatures stay around 55-70˚C under the current BIOS configuration, with core clock speeds at 5.0Ghz as intended.
There exists a more advanced stress testing program called AIDA64, which is free and less aggressive. It will also evaluate your FPU, CPU, Cache, RAM, GPU and disk with useful graphs to track during the process.
Now I understand your system, so here are some tips.
Avoid jumping directly to 5GHz; instead, increase in 200Mhz steps and perform stress tests while checking voltages and temperatures along the way.
Turn off Cstates as it is a power-saving function that may ruin a good overclock.
Use the multiplier only for overclocking.
Make sure any changes to the BIOS are deliberate and well understood of their effects.
Stay simple until you fully grasp your BIOS.
Adhere to a solid Overclocking Guide.
A decent overclock can be achieved by disabling Turbo mode and enabling all-core overclocking.
Here is a video as a starting point, even though it differs from your setup, the main ideas remain similar:
View: https://www.youtube.com/watch?v=PXMNgxM8RLE