If you have a good Nvidiacard (from GTX 660 I think) you can use Shadowplay from Nvidia. The best in terms of resources (uses a chip on the card itself), takes almost no hit. The sound is not that good though, but in general the quality is OK. Next in line for me is MSI Afterburner, better on all accounts, even though it takes a bit of resources. But the latest version is better on that account, and you can customize things alot. Fraps is also good, except that it takes far too much resources, up to like 50% in FPS. Try different ones, and see what fits. Good luck!