I was wondering the difference because I'm probably going to get an Alienware soon and one of the options for a hard drive was a 1TB 5,400 RPM + 64GB mSata caching drive for $225, then there was a 500GB 7,200 RPM + 128GB mSata boot drive for $175, and I was wondering if there was a better one out of those two. I heard that the caching loads files faster but takes longer to start up, and the boot starts faster but loads files slower, and I was wondering which one is better or worth spending more or less money, and it's all a little confusing.