It's perfectly normal.

In my experience all rendering programmes will max out your CPU when rendering. Some like Reality/Luxrender offer the option of setting how many CPU cores to use, but most will just use all the cores/threads.

If you didn't already know, the maximum number of cores/threads you can use in Vue Complete is 8.

You will probably find you can still do other low level things on your computer while Vue is rendering, such as listening to music, watching a movie or using a browser, etc. But something like playing a CPU intensive video game is a no-go

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