FPS problem in large GMod maps.

Before I get tot the point, I would like to announce that this is not another one of those rants saying, “WAAAAAH I MES GMOD 12/11!!! WAAAH!” Nope, I’m just wondering if there’s a fix for this.

In GMod 12, I could play maps such as gm_bigcity, rp_evocity, and other particularily large maps with decent optimization (like, 20-30 FPS maximum, maybe.). Now, in GMod 13, I run at a maximum of 5 FPS on these maps. I don’t know why, but with this poor optimization, my favorite maps are basically unplayable, you can say.

I did install CS:S content, which was 1 GB, but even that wasn’t an issue in GMod 12. Help?