I've had the piece of mediocrity known as the stock 2600Xt since I bought my Early 08 Mac Pro almost 2 years ago. I've started to get into some more GPU intensive graphics apps lately and I'm finding myself very limited. I used to be a PC guy so installing a new card was simply a matter of installing the drivers and all was done. But as I'm looking through the threads here, my noobness is really starting to hit me hard. I haven't yet installed SL, but I'm reading about things such as OpenCL compatibility (which my current card apparently does not have because of Apple's refusal to write a driver) and QE and wondering if this is all worth it. It seems that Apple is changing their architecture constantly and cards are becoming useless or limited left and right. I looked through Apple's very slim and VERY overpriced selection on the Apple Store, and came away less than impressed. I also read up on flashing a card (particularly the ATI 4890 thread) and am a little hesitant to do this, especially since the ROMs will continuously become incompatible as Apple makes Leopard updates. I know my ignorance is a bit pitiful, but I would be extremely appreciative if someone has the time to help me clear this all up. It's not that I don't understand GPU hardware specs, but my lack of fundamental understanding of the Mac-specific driver issues and new OpenCL architecture (as opposed to OpenGL?) are making me fearful that I will make an uninformed decision. My ideal solution is something that works out of the box with my machine (assuming I upgrade to SL) and will simply require occasional driver updates. But I'm getting the feeling that unless I'm willing to pay top dollar, this is going to be a hell of a lot of frustration. Any help (in terms that someone with my limited knowledge of Mac graphics architecture can grasp) would be more than appreciated!