I agree with you that users with old graphics cards would be having troubles. However, the game does specify that it require a graphics card that supports DirectX 9.0 (making miniumum required graphics card a Nvidia FX, ATI X600 or ATI Radeon 9500) so if you have one of those cards, your out of luck or have to turn to the Oldblivion mod. Unfortunately, Oblivion does not check for needed features on the card, it just checks if Transform & Lightning is available, meaning that if your card is below spec, Oblivion runs just fine but you notice pretty quick that something is wrong when the graphics comes out all garbled.
The first time I tried to run the game I owned a Geforce 4 card, hoping that if I just turned down the graphics settings enough, I would be able to play even if my system was below minimum specs as that technique had worked great for me so far, but I had problems immediately in the character creation process where the entire screen was filled with a single color and my character existed in the middle, only visible as two floating eyeballs. I never tried playing beyond that point, as something clearly was very wrong, maybe it would have eventually lead to a strange crash at some point. A short while after that, I replaced my card with a Geforce 6 series instead and this time everything worked as it should have, while it still was slow in some parts, at least I could see everything that was supposed to be there. Also note that all this was happening on Windows XP, so if Crossover behaves in this way with an old graphics card, at least it does the same thing as Microsoft's line of products. 😊
Im sorry to hear that the Mac has bugs in the OpenGL libraries, but pressure to fix things here belongs to Apple instead of Codeweavers. So to conclude, in my opinion, Crossovers compability to run Oblivion deserves more than Honorable Mention, at least given proper hardware and a bugfree opengl system 😉
Oblivion on my system
