Too much memory consumption while running code on drools6.

The memory usage on drools6 is far more then drools 5. Can we run the drools6 code with Rete algorithm?

We recently migrated our project from Drools 5.3.0.Final version to Drools 6.2.0.Final version. In production we can see a significant increase in the memory consumption per node. we are using java 1.7. We increased the permgen space as well for drools6 from 0.5 GB to 1 GB but still the increase is too much. Is there any solution for the same.
Drools5 memory usage was 0.5GB per node with 0.5GB permgen space
Drools6 memory usage is 1.3GB per node with 1GB permgen space.

Node here is a jvm as we are using oracle coherence.

If further details are needed , let me know.