There's some information we'll need first. Find out exactly what kind of hardware you're running. Assuming you're on Windows, download CPU-Z. It should give you a lot of useful information, the kind of information that you should have listed in your profile, e.g. CPU, GPU, RAM, etc.
Also, click the Config button in Dolphin and look at the General tab. Click on the Graphics button and look at the General, Enhancements, and Hacks tabs. Tell us those settings; you can take screenshots if you want to.
Lastly, which games are you trying to run? Check out the Dolphin Wiki for specific game settings. You can also find out how certain hardware will perform on those games via the specs users have posted there.
Also, click the Config button in Dolphin and look at the General tab. Click on the Graphics button and look at the General, Enhancements, and Hacks tabs. Tell us those settings; you can take screenshots if you want to.
Lastly, which games are you trying to run? Check out the Dolphin Wiki for specific game settings. You can also find out how certain hardware will perform on those games via the specs users have posted there.