I find that setting the power profile to "Power-Saver" makes a huge difference.

KDE has support for that built-in, although I'm not sure, if distributions install the corresponding daemon on desktop systems: https://gitlab.freedesktop.org/upower/power-profiles-daemon

You should be able to cycle through power profiles with Meta+B on KDE.
You can also see and change the profile via the systray icon for the battery, but on a desktop system, that presumably won't be shown by default.

Otherwise, powerprofilesctl is also an option, as described in that link.

I am speaking from decades of experience when I say the following:

No one can help you with this particular problem in any serious way if you don’t post your cpu and gpu models.

If you are on a laptop or some brand of desktop you need to post the model for that too.

As others have asked, desktop or laptop

But also where is it? If it's a "desktop" but on the floor in a deep carpet, tucked against the dark corner of the room under a desk, that's not going to help... bring it out into the air...

And for a laptop... lift it off the desk

I created an MDF raised deck for my laptop, with a massive slot where the fan intake is underneath, that really helped it breathe.

Looking to the future, if cooling is going to be a problem, I like to over spec' the equipment and underutilise it - it's better to run something twice as powerful at half the load... this knowledge came from the hifi world.

may help to know your device models, but power limiting is generally what you're after. Your hardware may determine the methods used.

Yes.

• LACT for GPU: https://github.com/ilya-zlobintsev/LACT

• For CPU: https://wiki.archlinux.org/title/CPU_frequency_scaling#Configuring_frequency_boosting

The default KDE power saver profile also disables turbo, and is configurable exactly like you asked.

But, like others said, we can’t really help without any hardware info.

Everyone: help me lower temps \
Me: compiling 100 GB worth of shaders for gaming on ultra settings in a room that's 30 degrees Celsius without the slightest afterthought. MAKE YOUR MONEY, NOCTUA FANS (six for chassi + two for CPU)

Also, look into undervolting 😊 although I know it's tricky, to say the least, on Linux...

An easy first step is to check BIOS and see if you can simply increase your fan speeds there for an immediate gain.
Another easy quick fix is to add a normal desktop fan placed so it pushes air towards your intake fans.
Third cheap way is to check what fans your case has today and what fits in it. Even the cheap 120mm fans from Arctic or Thermalright can increase airflow and lower temperatures.

How about buying a big fan that is for humans, but your put it in front of the computers intake for fresh air, for additional support. Maybe you could also under clock the CPU from Bios a bit.

Have you cleaned your fans and re applied thermal paste because i don't think it should be doing that

Laptop or desktop?

Your CPU will handle 100c just fine. Intels turbo boost is designed to run the CPU as fast and hot as possible. Your CPU is designed to run at those temps for years and it will be fine.

GPUs tend to not like it as much. Smaller lower end GPUs tend to handle it better than bigger ones, but neither like running at their max temp all day.