Finally, I stumbled upon an old bug reported agains Ubuntu. This led me to think about my compositing manager - unagi. This is a fine piece of software that does just what I want. However it seems to be the culprit of the resume trouble. Simply restarting it gives me back all the power. I've yet to try the trick with process scheduling to narrow this down:

Running sudo chrt -r -p 20 [pid of X] solves the problem for me, while resetting with sudo chrt -o -p 0 [pid of X] restores the performance issues.

I will update here when I do.

While this kind of solves the problem, I'm open to other suggestions.

Finally, I stumbled upon an old bug reported agains Ubuntu. This led me to think about my compositing manager - unagi. This is a rather dangerously aged, but still a fine piece of software that does just what I want. However it seems to be the culprit of the resume trouble. Simply restarting it gives me back all the power. I've yet to try the trick with process scheduling to narrow this down:

Running sudo chrt -r -p 20 [pid of X] solves the problem for me, while resetting with sudo chrt -o -p 0 [pid of X] restores the performance issues.

I will update here when I do.

While this kind of solves the problem, I'm open to other suggestions.