how many slots i can run

hey
i want to open a private server on my computer on gmod
so the problem is my internet speed i think 
and i want to know how many slots i can run on the server

heres my computer stuff
processor: i5 4440 3.10GHz
ram: 8
win 8.1
graphics card: Sapphire Radeon R9 270X DUAL-X BOOST OC 2GB
and internet speed of 12.2mbps and upload about 1mbps