So I've been trying to use dolphin emulator for smash bros and it seems to work fine but then it will slow down to about 50% speed. I can hit the 100% marks but it will slow down at other times.
i7 2820QM
nvidia 555m
8.00 GB mem
Post your Dolphin settings. Click the Config button and look at the General and Audio tabs. Click on ghe Graphics button and look at the General, Enhancements, and Hacks tabs. Tell us what you have set, preferably as screenshots. Also, which Super Smash Bros. game is it, iirc Dolphin can emulate all 3.
Smash Bros Melee or Brawl?
Your CPU is fine. Speed drops from 100% to 50% are really weird. Make sure you aren't overheating
Try changing settings and replaying, until it seems right, However, it would be better if you could post your settings, and then maybe we can figure out what's giving you a speed headache.