pip window swapping performance

[Ozbert]

First thing to consider, are you running multiple copies of wow or one copy?

d:\WoW3
  Cache -> linked to d:\world of warcraft\Cache

Are you sure linking the Cache folder is safe? It seems to me that it's only safe to link folders that WoW doesn't attempt to write to while the game is running. Cache is not such a folder. I'd expect it to cause major problems if multiple WoW instances kept modifying a shared cache.