View Storage Accelerator memory footprint

I'm running View 5.1.3 with ESXi 5.1U1.  I'm exploring turning on the View Storage Accelerator (i.e. Content-Based Read Cache) feature during my next scheduled pool maintenance update/recompose. 

My question is the memory overhead, if I have the host cache set at the default 1024 MB, will that use 1024 MB of memory per host per pool?  Or is it just 1024 MB per host shared among all the pools that I turn on the host caching feature for?

If it is just 1024 MB shared among the pools with with host caching turned on, is there a significant performance improvement for this feature if I up it from the default 1024 MB to the max of 2048 MB? 

Thanks for the advice and help!