best iMac I can afford for Raw files work in Aperture 3
I'm looking to purchase a new iMac soon. I work mostly with a lot of RAW Nikon files with Aperture and I do a lot of adjustments with them. I'm debating between the 21.5" iMac but upgrading the processor to the i7, or, getting the larger 27", but can't affford the i7 with that model, would have to stick with the i5 processor. The xtra sceen real estate is nice of course, but would it be better to have the i7 processor since I could always add a second monitor to the 21.5" iMac for additional screen area for menus, etc...Would adding that second monitor affect my processing and/or graphics speeds at all, somewhat negating the xtra power from the i7 processor, or, would adding that 2nd monitor not really affect my processing and graphics power at all?
Also, the 21" and 27" base models have the same graphics card with 512mb vram, is that ok for Aperture with RAW file also?
Thanks!
Mac mini, Mac OS X (10.7)