[Nuson]

Yeah, 64 bit windows might be on the way, but it doesn't matter unless your design software also supports it. Also, I can run Inventor with my radeon 8500, but only on conservative settings. You may be able to run it fine on your ATI card, but they just have a reputation for having compatibility problems with Inventor; that's all.

On the memory front, esp if you're going to make drawings of large assemblies (.idw), you'll need at least 1 GB of ram. Autodesk recommends that some users enable 3 GB page files, which just shows how much memory you'll need to do large drawings (tip: don't have more than one sheet in such drawing files). When modeling (i.e. working parts and assemblies), however, you won't need as much RAM (seems strange that doing 2d drawings of your parts and assemblies would require more memory than working on the parts themselves, but that's how it works. I'd like to find out for myself why that is). Realistically though, you should probably just go with 1 GB of RAM. If you're running on a tight budget, 512 MB of RAM is ok, but not preferrable.