It depends on how you intend to use your system. 8GB will be plenty for many different tasks, and certainly for older games, but newer games on higher settings will likely benefit from having access to an increased RAM pool. Don't forget you may need DDR3 SDRAM if you are looking to upgrade a laptop or vice versa. Also if you are on a newer system you may well not need DDR3 (Double Data Rate) memory at all, but rather DDR4 modules or memory kit.