Yeah that is the issue with a dual card setup. They tend to put the slots only 2 spaces away just enough to leave room for the cooler. I tried a 4870 CF setup a while back and the top card would overheat at 100C. I ended up selling both and getting a 5870. You really need to make sure you have alot of case airflow and preferably a side fan that circulates air between the cards. 93C is pretty hot, but they are designed to run hot. As long as it isn't crashing I'd say go for it, but would try to increase airflow.