I'm no expert on this stuff, so anything I say could be totally wrong, but I have a few questions that could narrow things down.
What specific games are you getting this problem on? This is probably the most important piece of information. Is it just brand new games, or are you experiencing slowdowns on games you previously got good performance on? If it's the latter, did you make any changes to your setup recently (upgrades, major updates, etc.).
What resolution are you running at? I'm guessing it's probably 1080p since that's what most monitors run at, but if it's higher your performance is going to start dropping fast.
If you're only experiencing this kind of performance on newer games, and you're not running on crazy resolutions, then I have a few ideas.
It's possible that some games simply have some performance bugs on your system, especially brand new ones. Look around and see if anybody else is having issues with the same games as you.
You might have some issues regarding using AMD cards. AMD cards traditionally aren't as well supported as NVidia cards, and it's possible some games aren't well optimized for them. Again, look into stuff for the specific game and see if anyone else is having the same issues as you.
Now, if there is one weak point of your system, it would probably be your processor. Now, don't go running out and buying a new chip just because I told you to, but it definitely is weaker than your GPUs, and that could easily create a bottleneck.
Honestly though, I think the real issue is simply we're in a state where things are advancing much more quickly than the past couple of years. Even absolutely insane machines aren't going to be able to max out everything that comes out in the next couple of years, not right away, at least. I think people just need to get used to the idea that they can't expect to max out everything on every game for the foreseeable future.
