idrezzz on "[Plugin : wp super cache]my vps overload when deleting cache"

My VPS get overload ( memory space constanly decrease ) when i delete all cache via "Delete Cache" button in Contents Tab . My site has high traffic visior with 300.000 page views per day . Any one can help what is the best setting wp super cache for my website . i try many of various settings . but the problem still occurs .
thanks .