smangs

I am really interested in DCS: A-10C Warthog and I already own Black Shark, which runs fine on my computer. However, now I saw that A-10C will require a minimum of 512MB graphics memory but my Apple iMac only has a ATI Radeon HD 4670 with 256MB. Has anyone tried running it with a 256MB card? I don't care about running it at full visuals as long as it's running smooth with lower settings. Thanks, smangs