VTdecoderxpcservice takes 600% cpu

Hello loreto5248!

Thanks for using the Apple Support Communities!

I see from your post that you have a process on your Mac that is taking a lot of CPU resources when your Mac enters into screensaver mode.

For this particular situation, I recommend that you reset your Mac's System Management Controller (SMC), and following that, reset your Mac's NVRAM as well.

If the issue continues to persist, try testing for the issue with a new user account: How to test an issue in another user account on your Mac

Kindest Regards.

In Applications->Utilities->ActivityMonitor, you can see what resources (CPU, Memory, Energy..) VTdecoder… uses and whether that is continuous or not.

Check that this app/version is compatible with Mojave, for example on www.roaringapps.com.

Check that you have the latest version, but maybe that is not (yet) compatible.

This is what is shows

I also have this issue, clean install from USB and recent unrelated logic board replacement. Have reset SMC and PRAM with no effect, certainly software issue but unable to resolve.

Seems like a bug?

This article is old, but I'd assume it is still relevant - at least it explains what it is:

VTDecoderXPCService sucking up 25-30% of … - Apple Community