Lightroom 3 and virtual memory?

Hi, as Adobe support cannot answer the question maybe someone else can, basically all I need to know is does Lightroom 3 access the drive where the software is situation for virtual memory or the drive where the photographs are located. Simply put my LR3 software is on my "C" drive whereas the photographs are on my "H" drive both internal hard drives.

If it uses C drive then I can replace this drive with a faster unit so that when LR3 needs to use a lot of virtual memory - as it does - whether ram is available or not then installing a faster drive would speed up the process and reduce its want to go white screen and crash.

I have a Dell Workstation, twin 2.83 quad core xeons with 12 gig of ram and the hard drive is the only part of my system which gets a lower performance score.

Help please!