No, it's not. Even if he has heavily overclocked a8-3780k with some fast 1866+ memory, 6550D is still worse (in gaming) than discrete 6570 in similar system.
The advantage of 6570 would be minimal, though.
Bejusek, a Radeon 6550D with dual-channel DDR3 1866 9-9-9-24 and a heavy overclock can be about mid-way between the Radeon 6570 and the Radeon 6670 in most games. It can beat the 6570 with ease. At stock with DDR3-1333 memory, the 6550D is much closer to the Radeon 5550 which is slower than the 6570 and at stock with DDR3-1600, it's between the 5550 and the 6570, but the 6550D can beat the 6570 in some situations.
Kamen_Bg is right about your friend's graphics being on the CPU die (or more accurately for AMD terminology, the APU die), not the motherboard, but without knowing what APU your friend has and the memory configuration, we don't know how it would compare to the 6570. I'd assume that it is weaker, but that's just a guess given that most people don't have very fast RAM nor do most people overclock and your friend probably also doesn't have the highest end A8s.