size of memory cache in bytes

[Zsolt Varszegi]

Hi,
 
I would like to know if it is possible to query the size of the memory
cache in bytes (as opposed to number of objects)? 
 
- If yes can this be done on the group level or only on region level?
 
- If no what would be a(n easy) solution in your opinion if we still
would like to do it?
 
Regards,
 
Zsolt