sounds that you should work rendering the biggest galaxy!!! is a disgrace you need to invert/put/waste too much money just using ASD, other programs run full mode using 2gb RAM.
Lanzman you have best computer, no need to change it, man i have just a regular laptop with core 2 duo, 8gb RAM and Nvidia geforce gts 9800m, and 6 months ago i just switch from ASD to Graitec Advance steel who also works on Autocad platform and from my experience Graitec can magae Autocad better then Autodesk itself, When i was working with ASD even for small projects my Ram was always on 100% but now max used RAM with Graitec is just 3 Gb for bigger projects. My opinion is stop investing in your beast machine just invest in new software
I agree with ZHUKOV_ING about the absurldy high system requirements of ASD compared to Advance Steel . Bottom line is that the 3D model appearance is quite the same (except that in Advance Steel the welds are just a cross symbol) but AS is much lighter that ASD , so it's not an impossible task to make the program much lighter , it's its biggest flaw.
PS AS is a great program but it has quite a few things that in my opinion are much better in ASD . If I could combine the two programs into one it would be almost perfect .