Unvanquished is an open-source FPS game featuring team-based strategy and RTS elements, pitting humans against aliens in a futuristic setting.
https://forums.unvanquished.net/
I noticed that when holding a ckit, my fps drops to 5, but when I switch to a weapon the fps returns to normal instantly (20 - 30 for me). This doesn't happen when I'm playing locally. Same thing happens with granger.
That would be the range markers. Have a look in the options menu (in-game) and switch off the line drawing – you'll still see a drop where range markers are drawn, but only a small fraction of what you see with the lines.
Alternatively, type these two commands into console or chat:
/seta cg_rangeMarkerDrawIntersection 0
/seta cg_rangeMarkerDrawFrontline 0
Just curious. Why does this affect builders only?
Since build ranges are only visible when you are a builder.