I need some advice on choosing a processor. I have ruled out the i7s as I read they are noisier and I am sensitive to noise. I have a 2009 24" iMac which is on its last legs but my main issue with it is that I can't even load Chrome without the fans whirling away. I have to run an external fan as well to stop it from being totally hot all the time. The noise is annoying while I'm working. I will use the iMac for some daily video conversion/compression in Handbrake, some programming with IDEs, photo editing in PS/illustration in Illustrator/testing web pages and applications. I may in the future want to test some games/VR but it is not something I need right now. I can stretch budget wise* to the 580 so wonder if I should just go for the best processor in that tier - but if it will be noisier than the other two then that would put me off. How useful is it to have 8GB for the GPU in the 580 over 4GB in the 570/575? I would hope to keep my mac for a number of years. Whichever processor I get, I will be upgrading to a 512GB SSD. I'd be grateful for any opinions on the relative noisiness/usefulness of the i5s. *I have the educational discount access so the prices are slightly less steep between the models.