Base iMac '11 27" and Thunderbolt monitor

I'm saving up money to get an additional monitor to enhance my workflow, and I figure I should opt for the Thunderbolt display so that I don't see any jarring physical differences due to different monitor sizes. However, my question now is, I have the baseline 27" model. Would 512MB of VRAM be enough to keep the Thunderbolt monitor and the iMac running without issues? I'm primarily a translator and a teacher, so I don't see myself doing anything intensive, but I figure I'd ask.