For some reason, I can play the largest maps on multiplayer with 20 bots on the highest settings, and it won't lag one bit. But for some godforsaken reason, I can't play singleplayer on medium settings without horrible slowdown. Any ideas?
I had the same problem. What I did was turning of the dynamic glow and downloaded nHancer. The program will help you to improve your Nvidia card. nHancer - Advanced Control Panel for nVidia Cards it worked out for me, I hope it will work for you to;)
Sorry, I forgot to mention I fixed it, but thanks for the nHancer! But, there was something interesting I had to do. I was missing a few required files off of the CD so I couldn't un-install and then re-install, but if you got to my computer, right click on the CD drive that JK3 is in, you'll see a list, click explore, and you can see the files on the CD, look around for setup. Duoble-click on that and It will un-install it, then you can re-install it. That problem was bugging me for about a year now, hope that helps anyone.