Use a 600 GB on mine. I'm a big h2 modder as everyone knows. I have 20 different versions of h2 and h1, with about 986maps. mostly modded. Some are ones I made. Like my map that is over 2.5 GBs. It's a map that takes place on delta halo. The halo is fully explorable. Plus, there are drivable cov capitol ships.