Fps Problems in Gmod! Advice appreciated.

Hello, my name is derek.

I have had garry’s mod for a while now and i am tired of the constant lag. I get around 30 fps on rp_downtown_v4c without props and 15 with, maybe 30 on flatgrass and 20 with props. When there is alot of props the game is barely playable.
What really confuses me is that i can run gta v max settings at a constant 30 fps with v-sync, and get around 60+ fps on cs:go maxed out. All of these games i am playing on 1080p with all the latest drivers. Also my passmark rating is 1774. I do have two monitors.
These are my specs.
Cpu : AMD FX-4130 Quad-Core
Gpu : NVIDIA GeForce GTX 750 Ti
Ram : 8gb
Motherboard : ASUSTek COMPUTER INC. M5A97 LE R2.0

Please tell me if you need more info or have any insight about this.
Any help is appreciated, thank you!

Bump!

Try to update your drivers and try to disable some addons you dont use, what is your windows version?

Windows 10. Thanks for the advice, as for the drivers i have stated that i have all the latest drivers.
All of these games i am playing on 1080p with all the latest drivers.

i do have some lag too on windows 10 in gmod, i play darkrp. go to gmod right click it then set launch options then type -dxlevel 80

Will do!

you pretty much just need to upgrade your CPU if you want better FPS, yours is a little old and not super great