i'm getting random stutters in both of the allowed sourceports. my cpu and physical memory usage are both below 30% so it should be running fine. is this a common problem? is there a way to fix it?

additional info: it only happens once every 3 or 4 minutes or so, and it's happened during crucial tricks causing me to lose runs. it seems to be worse in joequake than in neaquake. vsync didnt help.

update: fixed it. for anyone having the same problem in the future: i went to my nvidia control panel and changed "threaded optimization" from "auto" to "off". then i started up joequake and turned on vsync. fixed it immediately.