Basically, Chameleon runs Python, and Python is inherently single threaded. On a multi-processor system (or even on a single-processor system), all threads using Chameleon will be serialized on Python operations. This is also true even if they have one engine per thread. All load of VMD file operations are also serialized across all Chameleon engines.

Typically, Chameleon does not use both processors with multiple threads. If you reduce Python usage and control when VMD files are opened, you may notice a slight increase in performance.