Memory available and configured for named chaches

Bonjour,I'm running a Sybase ASE 15.7 Cluster Edition database and I just found something wierd about caches and very few literature about it.

I am refering at the middle section of the sp_helpcache procedure. The memory available for named caches is lower than the memory configured to named caches.

Is this normal behavior? How can I increase overall memory allocated for the caches? Is there any good literature to help me understand the mecanism behind all this?

Memory Available For Memory Configured
Named Caches To Named Caches
-------------------- ----------------
71837.9 Mb 77300.0 Mb