Question on memory utilization

 We have a T3-1 server with 64 GB memory. Below are the zones running on the server and as per "prstat -Z", the memory consumed by all 4 non-global and global is < 50%.

ZONEID    NPROC  SWAP   RSS MEMORY      TIME  CPU ZONE                        

     0       61  261M  339M   0.5%  10:09:26 0.0% global                      

     3       54 3069M 2914M   4.5%   6:48:52 0.0% appzone                

    23       32 2088M 1692M   2.6%   2:46:23 0.0% p2zone

    24       84   14G 7114M    11%   4:49:03 0.0% p1zone

     4       54   17G   16G    25%  10:11:06 0.0% ldapzone

Whereas our monitoring tool and "top" command shows that only 1.7GB left (> 90% used).

How to find which process is consuming memory or are "top" and monitoring tool is wrong?

Clarification on this is really appreciated.

Thanks In Advance

Moorthy