First of all let me give you the specs of my machine :
Asus FM-A85X-M/CSM FM2 Motherboard
A10-5800K CPU w/ Radeon HD 7660D
Radeon HD 7750 Double Diamond OC Edition
G-Skill Ripjaws X 2133mhz 4x2 For a total of 8 gigs
Seagate baracuda 500Gig 7200 Rpm drive
Orion 585 Watt Power Supply
Generic M-ATX CASE
Corsair H70 Liquid Cpu Cooler
Windows 7 Home Premium 64Bit
Now that is out of the way i can tell you that i have the 7660D Onboard GPU running in Dual Graphics Mode with my Radeon HD 7750 using Catalyst Drivers version 13.1. And yes it has given me at least a 20FPS framerate increase in games i play Guildwars 2, The Secret World, The Sims 3, Simcity the new one just released and many others. I am loving it Try it out i know i don't regret it.