Installation & Licensing

[#1]

Is there anything that I can do to make AutoDesk Building Design Suite Ultimate 2013 run more efficiently on the following models of hardware? I know when we went to the 2011 Edition I had to enable the 3GB switch in Windows XP so Revit would stop crashing.

AutoDesk Building Design Suite Ultimate 2013 - Specifications:
http://usa.autodesk.com/autocad/system-requirements/
http://usa.autodesk.com/revit/system-requirements/

HP Compaq dc7800 Ultra-slim Desktop PC
http://h10010.www1.hp.com/wwpc/us/en/sm/WF06b/12454-12454-64287-321860-3328898-3459242-3459247-36933...
Processor: Intel Core 2 Duo (E6750 @ 2.66GHz)
 
HP Compaq dc7900 Ultra-slim Desktop PC
http://h10010.www1.hp.com/wwpc/us/en/en/WF06a/12454-12454-64287-321860-3328898-3785404.html?dnr=1
Processor: Intel Core 2 Duo (E8500 @ 3.16GHz)
 
HP Compaq 8000e Ultra-slim Desktop PC
http://h10010.www1.hp.com/wwpc/ca/en/sm/WF06b/12454-12454-64287-3328898-3328898-4065899-4097378.html...
Processor: Intel Core 2 Duo (E8500 @ 3.16GHz)

HP Z400 Workstation
http://h10010.www1.hp.com/wwpc/us/en/sm/WF06a/12454-12454-296719-307907-4231338-3718668.html?dnr=1
Processor: Intel® Xeon® Quad-Core Processor W3520 (2.66 GHz, 8 MB cache, 1066 MHz memory)

All Models will run Windows 7 Enterprise 64bit with 4GB of RAM.

[#2]

4gigs is probably not enough

i would start at 8 gigs and go up from there