Hello!

The maximum frame rate seems not to be limited by default: as soon as I turn off vsync, the cpu usage of the client goes from 20% to 100% (even when I'm still in the login screen).

Furthermore, this seems to have no impact on how my graphics card is performing, so my guess would be that whatever is hogging the cpu isn't directly related to rendering but is just done once every frame no matter what - can that be right?

This high cpu usage at first glacne seems to negatively affect other aspects of the client. I seem to get lag more often. Though I couldn't figure out how exactly (I'm not very good at this), my network activity seems to change. Are there other things the client is neglecting while doing redundant per-frame stuff? I didn't test too extensively as this can easily be avoided by turning on vsync. Maybe most of what I saw was coincidence, but this could be worth further investigation if someone has more trouble with CPU usage ;)