When I compared the 850TX and the 850HX side by side, I noticed that the 850HX does not say it is crossfire or SLI ready. They both have the same wattage. Why wouldn't it be SLI or crossfire ready? Is that just a marketing gimmick?
Also, on the output rails, the 850HX has 5 less amps on the +3.3 volt and the +5 volt rails.
EDIT: I feel really stupid right now but I just realized that my PSU has a 3 year warranty on it. I could have found out if my PSU was causing the trouble without having to buy a new one. I don't know why I didn't think of that before. I am mad at myself right now. Oh well, what's done is done.