Corsair H115i v2 vs Cosair H100i v2

H115i is 280mm by 140mm dissipation surface while the 100i is 240mm by 120mm dissipation surface. h115i is better due to larger surface but the pump is identical. Depending on space available in your case h115i is better but if you dont have room for a 280mm radiator then a 240mm radiator should be ok too.