Hello gents, thought I would place this out here. I have (2) GeForce  GTX 560ti Femi at a  core clock of 900MHz. Yes I understand that most of these cards run at 850MHz & 833MHz. The cards are no more than two months old, and that's stretching it. I have them running in SLI mode and they work GREAT. I just want to upgrade to the 600 series.....I'm asking 450.00 for both cards, or 225.00 for one.....If this sounds good to you, please contact me.....