I have an Acer Aspire 7745G laptop. The freshly installed Ubuntu shows in the settings that the Intel Ironlake Mobile is found, but not the ATI. When I go into the BIOS and switch the Graphics mode to discrete, the screen gets all grainy (during the boot up already), and Ubuntu still just finds the Intel chip.
I tried to install graphics drivers from ATI but without success, maybe I did something wrong? Installing the proprietary ATI drivers doesn't seem to work, as the software doesn't find the device as expected. When I had Windows I had the same problem: the normal ATI drivers didn't work, but the one Acer provided did.
Apologies if there's already a question like this, but all the other questions related to my problem weren't specific enough. Sometimes I followed instructions which caused Ubuntu to crash while booting, so I'm cautious with any random advice not related to my specific problem.
I'm relatively new to Linux, but I definitely want to stay there. I hope this is enough information for you to work with, and I'd be very grateful for any advice.