If the Captain Sim 757 runs fine on my PC, would my system specs be adequate to run either the PMDG Md-11 or 747?

I've got to admit, I have all three, and for some reason the biggest FPS hog is the CS 757. The 747-400X is an incredible package, and I would highly recommend it, and it runs better than the 757...The MD-11 even runs better than that. I am in no way affiliated with PMDG, but their support, visual model, and especially realism and systems destroys Captain Sim. I am a real-world 757/767 F/O for a US airline and would rather fly the 2 PMDG products...Just my 2 centsJon