How to find out which node package is better in performance

I have a large xml which needs to be processed to extract a small amount of information. I found two packages which can parse the xml tag-by-tag. The 2 packages are : xml-flow and node-xml

I would require a package which loads a part of the xml file and performs the operation. Since the performance will depend on the amount on file loaded in memory (which I want to be smaller), I am looking for a way to measure that in the running process. How can I profile the memory in a simpler way?

via Prateek