performance tweaking for a hd6570

[printf]

after getting fed up with windows becoming very slow on my thinkpad t60p, decided to get an ssd and install only gentoo on it.
i am using the Thinkpad advanced dock, which lets me to use a small form factor pci-e video card.

so far after installing gentoo and setting up the system, everything is working as i excepted:
-uninegine tropics benchmark gave good fps
-installed steam and some ~3d heavy games and they ran rather nicely
-team fortress 2 has some problems like no sound and no 3d models in the equipment view, but i think i can fix that

the next step was installing diablo 3 via wine, using the development version (currently 1.7.x), and suprisingly everything went smoothly, no tweaking was needed.
my only problem is that i got a visible framerate drop in the game compared to when i had windows.
i know that i am running trough wine, but i think it still can perform better

few technical specs:
-the system is 32-bit
-using the open source radeon driver with the following VIDEO_CARDS use flasgs: radeon r200 (for the built-in firegl v5250) r600 (for the hd 6570)
-emerged the radeon-ucode package and the firmwares are built into the kernel
-if i remember correctly, the driver-related packages have the x86 keyword enabled on them, but they are not directly from the development branch
-system and the partition where diablo 3 is located are both on the ssd, as ext4

the gentoo wiki mentions something under the tuning topic (https://wiki.gentoo.org/wiki/Radeon#Tuning), but i don't want to risk it before i know that it is safe and it is worth it.

so the question is that are there any other performance tweaking options that i do not know of?