these kinds of things are always hard to identify without being on the computer itself. you can have identical hardware and get different performance from it due to firmware and driver upgrades. the guy above with his 100 FPS may have his computer set up perfect with nothing running in the background to interfere. and the next guy with the same hardware … can be missing windows updates that failed on install. out of date directx drivers or just out of date firmware. could be running multiple programs in the background from antivirus to firewalls. or even unknown malware thats using 10% of your cpu without your knowledge.
and you would be amazed at what a problem with a power supply unit can cause… especially one that causes rare problems or only under high performance (fluctuating power or not quite enough power to the video card aka a failing psu) … try identifying that issue without a spare power supply around. trust me its not fun.