I'm not quite sure. it requires alot because i have a computer with supposably a high ram. but gmod does not work because it is too low. sorry, that's all the info i can give you. but you could actually try to search in on the garry's mod wiki. =D
Garry's Mod 11 is about 150mb in size, but it imports the models, textures, etc. into the mod from other games installed on your computer that run on the Source Engine, like Half-Life 2 and Team Fortress 2. After it adds a large amount of that content it could end up being 1GB - 4GB, or even more, depending on how many Source games you have.
Buy Garry's mod 10 off of steam.
technically yes, there were a few updates it is still called Garrys mod 10 though
Garry's Mod 10
no because garrys mod requires that you have a game that uses the source engine
Garry's Mod has now updated and includes all features of 13 Beta
Garry's mod tornado
Steam
yes
You Do Not Get Garrys Mod Serials, You Buy it Off Of Steam Which can be found at steampowered.com its usually about 21 United States Dollars
E
no
You can't