Frequencies drop at 8700k clock speed
Frequencies drop at 8700k clock speed
Hey there, I've just begun experimenting with my 8700k and it's been a bit of a challenge for my GPU. My setup includes the NH-D15 MSI Z370 Gaming Gaming M5 MSI 3080 Trio. I managed to hit 4.9Ghz at 1.25V without pushing the limits or lowering the voltage yet. I ran Prime95 with AVX disabled and it performed well at 80 degrees. The problem is that the clock speed drops from 4.9 to 4.3 and stays there, whether under load or not.
I've tried changing EIST(Speed step) and Enhanced Turbo off, adjusting the AVX offset, and increasing power limits. Windows Power plan is Ultimate Performance Checked XTU, but it doesn't indicate throttling. I noticed that when I boot up, launching games like Warzone—which likely uses AVX—causes the frequency to drop to 4.3 and stay there until I restart. It seems there might be a BIOS setting affecting this behavior.
Any advice or guidance would be greatly appreciated! Thanks.
It’s quite unusual! Running at 80°C with AVX disabled is significantly higher than expected for an 8700k even under full load. I’d reset the BIOS to defaults and then adjust the overclock parameters again to check if it improves. Also, reattach the Noctua components and reapply thermal paste. Vcore should stay at or below 1.35 LLC, whatever setting suits you. Sync all cores, set 49 Uncore, and I believe mine is at 4.7 XMP – Profile 1 if XMP is enabled. Make sure Speed Step or Turbo are off, and turn off any C-State references. For non-AVX Prime chips, stick with version 26.6 to confirm AVX is disabled. To test stability, run Cinebench R20 or the CPU benchmark in 3DMark. AVX in Prime versions above 26.6 may cause issues but rarely crashes. For hardware monitoring, use HWInfo and watch core speeds, temperatures, and Vcore levels. Hit reset values and the timer button right before starting a Prime stress test to see how low the Vcore drops under maximum load. With a Vcore around 1.25v or lower, you might encounter VDroop problems – it’s a balancing act to keep it stable. My 8700k requires 1.35v and a strong LLC setting to prevent instability. Definitely try liquid metal if needed. This was probably the best solution for my i7 models, giving me a 10°C reduction.
Hi, thanks for the response. I definitely haven't reapplied thermal paste in quite a while, maybe I'll use this as a chance to delid as you mentioned... I always assumed 80C was fine in prime95 since it's a bit overkill but can't go wrong with reapplying paste anyways. And while I'm using a newer version of prime95, I added "CpuSupportsAVX=0" to the local.txt so I believe that's all I need but I can try some different tests. Never had my PC crash at any point, 3DMark my temps are 70 degrees, gaming also 70 degrees. Fairly sure I can drop my voltage a bit more as well to reduce temps but haven't tried yet. I'm assuming Uncore is the same as ring ratio? If so I had that set to 45. LLC I set to mode 4. XMP I enabled. Also, been using HWInfo for voltage and HWMonitor for temps/clock. Disabling C state is something I haven't done so I'll give that a try and check out the Vcore/Vdroop after. Thank you
It's unusual that the drop from 4.9 to 4.3 happens without noticeable throttling, especially since it only becomes apparent under AVX workloads. The fact that it settles at 4.3 even though BIOS settings weren't changed suggests an offset might be active. Updating or resetting your BIOS could help restore normal performance.
I haven't attempted disabling the C state yet, though... I just realized my BIOS hasn't been updated since I got it in 2017. I don't see the current version and can't restart the PC right now. Based on checking msinfo, I believe I have the original BIOS release. The patch notes for the next version mention... - Fix throttling issue when using a 8700 CPU during a Prime95 burn test. Not sure if this applies to the 8700K, but I might try that after switching off the C state.
I adjusted my BIOS, increased the ring ratio to 4.7, and turned off Intel C state which deactivated the other setting I noticed. The problem persists regardless of clock speed—whether I set it to 4.7, 4.8 or 4.9—it always drops to exactly 4.4. I’m confused about what to do next. When I ran Prime95 again, temperatures stayed very low until I realized my clock speeds were dropping and fluctuating between 3.7-4.2, with XTU warning about power limits. It seems like the throttling is happening even now. What else could be causing this?
Also consider the MBOO VRM ratings or whether your PSU isn't providing sufficient power if all settings are correct.