I have I7-7700, GTX 1060 6GB and 16GB RAM. Does anyone know do I have to specify somewhere in HitFilm Express to use GPU instead of CPU or is it that my Nvidia driver have some bug with HitFilm Express?
It’s not very common to see your system hit 100% usage during renders in any video editing software. Never mind that Task Manager’s usage reporting isn’t always accurate.
As far as the GPU goes, it is mostly only used to decode your original footage and it also takes care of certain types of effects. GPUs have different parts for different tasks that HitFilm can’t always take advantage of. For instance, a portion of your GPU is designed for Physics simulations in games, but most video effects don’t require any physics calculations, therefore, that hardware can’t usually be used by HitFilm.
There are similar limitations for the CPU.
Sometimes there are instances where the CPU is waiting on the GPU to finish a task, or vice-versa.
If you’re only using one drive, especially if it’s not an SSD, that’s a huge bottleneck. There may be other bottlenecks on your system that are a bit harder to find and fix, if fixing it is even possible.
tl;dr The behavior you’re experiencing is totally normal and is nothing to worry about. There might be some things you can do to improve it, but seeing 100% use is unusual on most half-decent systems.