Question PC sometimes starts with low core voltage - returns to normal on reboot

Nov 24, 2020
Sometimes when I start my computer, everything is slow (applications take several seconds to open for example) despite task manager showing no abnormal CPU/memory usage. It's been happening ever since I built this computer a few months ago.

I've been able to workaround around it by rebooting, which seems to fix it while the computer is on. The next time I boot up there's about 25% chance it will be slow again.

Over the months I've looked at possible causes:
  1. High page faults - didn't find anything to work with here
  2. Applications using high CPU/ram - nothing here either
  3. Windows Defender - no luck here
  4. Check temps/fan speeds - these looked normal
  5. CPU throttling? - I thought to look at CPU-Z when the issue happened today, and it showed a much lower core voltage and clock speed than normal:
Normal: View:

Slow: View:

After noticing that, I went into the bios to look at the CPU settings- the only custom setting I had was AI Overclock Timer: DOCP with my specific memory frequency set, and no custom CPU settings. I reset everything to defaults to see if that will fix it, but if that ends up being the solution I won't understand why.

Interestingly, when I looked now the voltage and core speed values seem higher on average: View:

Any thoughts on what's happening here, or what I should do? Thanks.

CPU: Ryzen 7 3800X
Motherboard: TUF GAMING X570-PLUS (WI-FI)
RAM: Corsair Vengeance LPX 32 GB (2 x 16GB) 3200 MHz 288-Pin DDR4 DRAM C16 Memory Kit, Black (CMK32GX4M2B3200C16)
CPU cooler: Stock
Video card: GTX 1060 6GB
Power Supply: Corsair CP-9020195-NA RM Series RM750 80 Plus Gold Fully Modular ATX Power Supply
Hard drive: 860 EVO
OS: Windows 10 Pro
Case: Phanteks Eclipse P400A
Last edited: