I expect you could save a few GB by RARing up the albums. Or you could use this as an excuse to buy yourself a nice new 20gb IPOD (or similar mp3 player) and use that for temp storage while you format.
or...
You could download sisoft saundra (sp?), i believe that has utilities for testing HDD speed etc. It also gives you tips on how to improve performace which might help. :/