It's also possible (though perhaps not likely) that your card is overheating and throttling itself to cope.
But yeah, if you and your friend truly do have identical GPU/CPU, and his rig performs much better than yours, then the most likely explanations are either that he's overclocking, or that something on the software side is holding you back -- whether it's a bad driver or bloatware on your system or your multitasking habits. Or perhaps your settings within the game itself are more different from his than you realize.
I doubt very much that your BIOS is the problem, but it's possible. Likewise, your memory settings probably can't account for the kind of disparity you describe; we're talking about more than a 50% FPS advantage for your buddy, on (supposedly) exactly the same hardware. That's huge.
All of that said, though, 40-45 FPS under the conditions you describe sounds about right for your hardware. Your friend's performance seems to be the outlier here, not yours.