RAM Cache showing almost 100% utilization, system memory used 212MB

Not sure whether this is the right place to post this, but I could not find a forum for general config issues.

 

 

We have allocated (in the http-profiles) 350 MB RAM for RAM Cache. RAM cache utilization (performance report) is close to 100%. However, system memory used is only 212 MB.

 

 

Based on this it looks like RAM cache is not really used (at least not 95+% of 350 MB).

 

 

Suggestions?