I doesn't own A+I PowerXpress so this post is just assumptions, I can't check it so I may be wrong.
Look into this ticket: https://bugs.freedesktop.org/show_bug.cgi?id=37686
As I understand you need TearFree feature of Intel driver, that available only with SNA and seems like work properly only since Linux 3.8.
But AFAKI fglrx need patches to work on Linux 3.8 and I doesn't sure, does fglrx compatible with SNA or not. So you may try to update Linux kernel, patch fglrx to make it work on Linux 3.8, and try to enable SNA and TearFree somehow (see link to ticket above to find xorg.conf examples). A little newer Intel driver package from ppa:ubuntu-x-swat/intel-graphics-updates probably include some bugfixes that may be useful.
Maybe it will help, maybe not.
I may have not make me very clear.
I only speak of the intel graphic card to show that my system can work as expected (with the intel card), and that the issues come from the amd driver. The issues I have only come when I use the amd card.
With the amd card:
. refresh rate of kwin is 70 fps whereas it should be 60 (and it is 60 with the intel graphic card)
. Tearings, even with vsync set to always, in cruisader kings 2
(. a missing desktop effect and issues with Xrender whereas everything work with intel graphics, but that I don't really care since it is not an important desktop effect and that I can use opengl instead of Xrender)
It seems that force vsync is broken: even glxgears gives me 1500 fps instead of 60fps when vsync is set to always.
It tried also amdconfig --vs=on and restart but it didn't change anything.
I tested with the beta6 drivers.
I've read the logs of xorg and I saw a line saying:
fglrx(0): TearFreeDesktop is not supported on PowerXpress systems currently.
So it may be related to my problem (though my desktop has no tearings).
So I hope that these issues will be fixed in the next release.
Vsync is still broken on my hybrid system with catalyst beta 13.6.
For example with the Portal beta, I can set vsync off/on.
With the intel hd 4000, vsync on work (and I feel a huge difference)
With the amd hd 7730m, vsync on or off doesn't change anything and I get tearings. For every other games, vsync doesn't work either.