Knime is slowing down

Hi all,

lately I´m realizing that my workflows run more and more slowly. I have all my workflows in the default workspace. I run all my workflows through batch jobs and windows task manager. I have assigned 4Gb RAM memory of 8 in my system in knime configuration file. Data volume managed by the workflows hasn´t gone up significantly.

How could I boost my workflows ? Maybe creating different workspaces?

Thank you very much.

Regards