thanks alot dave, yes am going to do what you told me , i am ordering same capacity tomorrow , and then il have 1 for primary and 1 for cache and others for storage.
just wanted to say if i used 300gb then the remaining gb is not enough for cache is it , on this hdd afer effects setting i set cache limit to 98gb to the folder , highest it reached 100gb i never had 150gb or over