Not particularly on topic, but I thought you'd like to know: the kind of problems Geniuses run into most frequently are people with iPhones that ran out of charge, saying it won't run, which they promptly fix and hand back.
No, I'm not kidding. I spoke to a few about this.
Basically, don't expect a ton of help if it's not something they actually see on a regular basis. In other words, 85% of the questions that'll get asked in this subforum. Very few will be able to answer questions usefully about a graphics card.