Raspberry Pi 3 speed? – Hardware

I dug my Raspberry Pi 3 out of mothballs recently to test it out. It’s a lot slower than I remembered… Altered Beast and Bad Dudes won’t even run at full speed! Is this the way it always was and I just don’t remember it? Furthermore, my switching power supply doesn’t seem to give it the juice it needs to run properly. I switched to a different power supply and while it’s running better, it’s still not as fast as I’d like it to be. Anyone have any suggestions as to how I can boost the speed on this system? Overclocking is an option, but it shouldn’t even be necessary for BAD DUDES.