<p>You could perhaps try:</p>
<pre><code>bitcoind -par=&lt;n&gt;
</code></pre>
<p>Where <code>&lt;n&gt;</code> is the number of script verification threads (-4 to 15, 0 = auto, &lt;0 = leave that many cores free, default: 0)</p>
<p>The script verification thread is heavily used during the Initial Block Download, so limiting the cores it uses during IBD may help.</p>
<p>This flag and other flags that could potentially help can be looked up with <code>bitcoind --help</code>.</p>

CC BY-SA 4.0
2022-02-15T10:06:35.940Z
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
CC BY-SA 4.0
2022-02-15T23:56:23.440Z
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.
stackaccount
CC BY-SA 4.0
2022-02-15T08:06:03.510Z
2022-02-15T23:59:09.333Z
2022-02-15T23:59:09.333Z
stackaccount
<p>I was able to solve overheating problem by disabling <a href="https://www.intel.com/content/www/us/en/gaming/resources/turbo-boost.html" rel="nofollow noreferrer">Intel Turbo Boost</a>.</p>
<p>ThinkPad X1 Yoga now runs 20°C cooler and fans are quiet… slower IBD, but I’m no longer worried about cooking my hardware.</p>
<pre><code>echo &quot;1&quot; | sudo tee /sys/devices/system/cpu/intel_pstate/no_turbo
</code></pre>

CC BY-SA 4.0
2022-02-14T18:18:51.470Z
2022-02-14T18:18:51.470Z
sunknudsen
<p>I am experimenting with Bitcoin initial block downloads.</p>
<p>One of my tests is running on a ThinkPad X1 Yoga and computer is getting pretty hot.</p>
<p>It it possible to manually throttle CPU to make computer run cooler?</p>
<p>It it possible to configure <code>bitcoind</code> to use less CPU?</p>
<p>Thanks for helping out!</p>

CC BY-SA 4.0
2022-02-16T00:57:47.477Z
@Prayank IBD only
sunknudsen
<bitcoind><linux>
How to manually throttle CPU to make computer run cooler?
sunknudsen
# How to manually throttle CPU to make computer run cooler?

(Asked by: username_0 on 2022-02-14)

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!

**Tags:** bitcoind, linux

> **Comments:**
> **username_0**: @Prayank IBD only  

---

## 2 answers

### Answer by username_1 on 2022-02-15. Score: 3

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`.

> **Comments:**
> **username_0**: 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.  
> **username_1**: 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.  

---

### Answer by username_0 on 2022-02-14. Score: 1

I was able to solve overheating problem by disabling [Intel Turbo Boost](https://www.intel.com/content/www/us/en/gaming/resources/turbo-boost.html).

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

```


---

