I previously owned a Ready Boost and 8GB of RAM before replacing it with a full 840 EVO SSD and 16GB RAM. It will improve the boot times for windows and a few apps but don't expect the same level of performance overall when comparing to a normal SSD. After restarting the computer a few times the software it comes with will automatically figure out what to place in the cache and overtime replace those items with others. I was pretty please with what I got at the time because you're basically turning your hard drives into a hybrid SSD setup.