why put the os on an ssd?

atomicWAR

Glorious
Ambassador
SSD throughput (data transfer speed) is much much higher than a mech hdd. you know how when you load a game it takes any where for 30 to 60 seconds to load up a level...with an ssd its nearly instant. or when you boot windows it will cut you boot time down to 7-14 seconds (from the windows splash screen to log in) where as a mech hdd could take minutes.
 
The best use at least for me is just for the OS. I have tried games on my SSD before and really the space used out ways any real benefit you might get in faster load time. However for the OS it is like night and day. I have a total of 3 SSD's in my system now because I boot Windows 8 Pro x64 Windows 7 x64 and OS X 10.8.3 and all three boot in seconds on the SSD drives it is really a big difference.

The one thing you would want to make sure on before you install your OS on a SSD it to be sure your SATA Controller is set to AHCI mode before you install the OS. If not any real speed gain will be lost.