Just thought i would post this for anyone having temperature issues with Ubuntu 12.10 on their macbooks. And give my thoughts and setup information that seems to be very reliable and stable.
I had decided that with OSX becoming more like iOS everyday that i wanted to move OS and keep my great piece of hardware. I love the screen and the quad core with 8GB of RAM is amazing. Good machine hampered by the poor OS...anyway!
I had the BIOS legacy boot working with reFIND but noticed that the temperatures were sitting at 70 - 80 idle. Which is not good for the laptop in my opinion. The fans were blazing away and it was making no difference. I did my research and it appeared that using the old BIOS legacy mode on your macbook which uses EFI caused issues with heat, due to graphics swtiching and other unkown reasons where making my CPU cores stay roasting hot.
I then installed the grub efi and edited my grub.cfg (which i will post once home from work). I kept the BIOS legacy working and installed the EFi version along side it in a different partition on the /dev/sda1 /boot/efi/EFI/ubuntu
This is where my 64 EFI image along with the grub.cfg are located this seemed different to everyone else's I had read about online, and i was having lots of trouble getting it to boot. I came very close to removing it all and starting again but i presisted and managed to get it booted.
Now my temps are 40 - 50 idle and graphics switching works fine. But i have been booting with my radeon card disabled because i dont need it and intel built in graphics are perfectly fine for what I use the laptop for. Keeps it cooler and quieter on my desk.
Also i have opted for another fan control package that doesnt get many mentions on the forums, its called mbpfan here is the link for its github. Its very good and seems to work with my model of macbook very well.
Some helpful articles are :
These guys are alot more intelligent than me and their articles helped me alot! So many thanks if you reside on these forums somewhere!
If anybody has any questions i will try my hardest to answer them. Also excuse my idiot spelling im sure there will be mistakes somewhere.