if the game requires a minimum of geforce 6600 then i dont think its not a difficult thing to run the game on 512Mb of ram. I have been running games on 512mb ram for a long period of time.... games like witcher, gears of war, crysis and COD4... so whydo people always ask if 512 mb ram will be enough?? in my experience if you can fulfil the processor req and vid req than you can run the game easily
Because games like Supreme Commander, (being the obvious offender) post thier system requirements as..
Required
Operating System: Microsoft WIndows XP Service Pack 2, Vista
Processor: 1.8 GHz processor
Video Card: 128MB video RAM or greater, with DirectX 9 Vertex Shader/Pixel Shader 2.0 support
Disk Space: 8GB available hard drive space
Sound Card: DirectX® 9 compatible Sound card, speakers or headphones
RAM: 512 MB RAM
DirectX: DirectX 9.0
Recommended
Processor: 3.0 GHz Intel or equivalent AMD processor or better
RAM: 1 GB RAM or better
Video Card: 256 MB Video RAM, with DirectX 9 Vertex Shader/Pixel Shader 2.0 support (Nvidia 6800 or better)
Where the minimum req's will "BARELY" play the game and the manufacture "RECOMMENDED" settings require the video settings to be seriously scaled back to low/medium. I think people are a little justified in being unsure as many publishers are obviously not quite being fully up front with what the actual system reqirements are these days. (stardock is not one of them fortunately, but people new to how great this company is wouldn't know that yet)
mind you having said that my current computer with it's Intel Integrated Graphics (which totally suck yes but according to system reqs, shouldn't) can barely play Gal Civ 2 Dark Avatar and by all indications is should be fine.
besides memory size is not always the best indicator of video card performance. my wifes laptop has a 310 Mb integrated Graphics card and the 256MB dedicated card in my new machine has kicks it's butt hands down.