Any hard drive won't get near the performance of a good solid state disk. Although I wouldn't buy any SSD without knowing which one it really is. Here's the problem with that $600 SSD drive Alienware lists...
http://www.anandtech.com/storage/sho...px?i=3631&p=19
"The largest SSD maker in the world is Samsung. Samsung makes the drives offered by Apple in its entire MacBook/MacBook Pro lineup. Samsung makes the drives you get if you order a Lenovo X300. In fact, if you're buying any major OEM system with an SSD in it, Samsung makes that drive.
It's just too bad that those drives aren?t very good."
That's putting it lightly, they just suck.