2010-08-09 02:20 AM
Hi CP and welcome to the Communities!
PAM II (a.k.a. Flash Cache) will be beneficial for only certain types of workloads, namely when your hosts frequently read the same data again & again. If your read pattern is different, then PAM II will not help. Also be sure to 'warm up' the cache (fill with data) before doing any testing.
Here is a bunch of documents explaining all this in much greater detail: