I am experimenting with Bitcoin initial block downloads.

One of my tests is running on a ThinkPad X1 Yoga and computer is getting pretty hot.

It it possible to manually throttle CPU to make computer run cooler?

It it possible to configure bitcoind to use less CPU?

Thanks for helping out!

  • Are you doing anything related to wallet or its just IBD with no wallets loaded?
    – user103136
    Feb 16, 2022 at 0:56
  • @Prayank IBD only
    – sunknudsen
    Feb 16, 2022 at 0:57

2 Answers 2


You could perhaps try:

bitcoind -par=<n>

Where <n> is the number of script verification threads (-4 to 15, 0 = auto, <0 = leave that many cores free, default: 0)

The script verification thread is heavily used during the Initial Block Download, so limiting the cores it uses during IBD may help.

This flag and other flags that could potentially help can be looked up with bitcoind --help.

  • Thanks for sharing! I tried that, but even par=1 lead to overheating… I believe par is intended to free resources for other processes rather than mitigate overheating. That said, my use case is perhaps hardware-specific. Great answer though… it will likely help others.
    – sunknudsen
    Feb 15, 2022 at 10:06
  • Thanks for trying. Hopefully someone else can shed some wisdom on this, as I am curious and a bit surprised to hear that that doesn't work. It seems par was designed to limit core use and to me it is implicit that that should also mitigate overheating. I am not exactly sure how to actually check how many threads run, but if all threads still run on all cores even after flagging it, it may mean that par is not/no longer working as intended and it may need to be reported as an issue in the repo. To limit CPU use is a reasonable functionality to ask for to prevent machines from cooking. Feb 15, 2022 at 23:56

I was able to solve overheating problem by disabling Intel Turbo Boost.

ThinkPad X1 Yoga now runs 20°C cooler and fans are quiet… slower IBD, but I’m no longer worried about cooking my hardware.

echo "1" | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo

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