Try Ecotect for Free

Autodesk has recently purchased Ecotect and is making the software available for free (trial basis) on this site...

http://ecotect.com/downloads

Ecotect is an environmental simulation software.

Revit 32 and 64 Hardware Benchmarking

Towards our ongoing conversation regarding hardware I found this blog which is benchmarking with Revit(32 and 64).

http://archin3d.blogspot.com/2008/10/revit-64-bit-benchmark-results.html