That sounds like normal, pressure testing/benchmarking are completly different than real world tests. Are you sure your not running it on enthusiast settings? If so lower it to get better FPS. What you should be more concerned with is FPS in games, because benchmarks really dont mean anything unless your overclocking with the absolute best stuff.
Another suggestion would be to go into the Nvidia control panel and make sure single display performance mode is checked along with prefer maximum performance under power usage settings.