When browsing Infinispan subsystem Firefox starts using too much memory.
I entered to Infinispan four times in total and hit ctrl+f5 after first three enters and after browser reloaded I entered it again.
After first enter the peak value of memory usage was around 1.2 GB, after fourth enter the peak value was 2.2 GB for standalone mode and 1.9 GB for domain. You can see memory and CPU usage in graphs and raw values in logs in attachments.
Left Y axis describes CPU usage in percents, right Y axis describes usage of memory in kilobytes, X axis describes time in seconds.
First column in logs is pid, second memory consumption and third is memory usage and third is CPU usage in percents.

The data was logged by ps --pid $PID -o pid=,size=,%cpu= command running in loop, the PID was PID of Firefox browser itself. Selenium was not used at all in this test. I did not compared it to other browsers.