I had a question relating to the new iMac too:
Does anyone know whether the Nvidia Quadro cards offer any improved performance in resolve over the non-pro cards (GTX) other than clock speed and cores? Does the same apply to mobile(M) cards as well.
On paper the Nvidia 680MX in the new top-end iMac kills the Quadro 4000, which is DaVinci Resolve approved. The 680MX is also cheaper. What's the downside? I know they lock out some 3D developer features, but is their any downside if you are just doing video editing?
I don't know about the new GTX cards, but I had sold my GTX 590 with extra change to spare for a Quadro 2000 and the improvement was 4x better. I don't know much about the marketing schemes from nVidia but I can care less about the gaming performance. This just last year running CS5.5 I noticed a significant difference in realtime plugin performance for the 590 and the Quadro 2000. I'm still gunning a Quadro 2000 atm. My rig is an Intel i7 990x (extreme) with a 24g RAM board on Win8. No need atm to upgrade as everything is still running smoothly even with R3D files. Either I didn't do settings right for the GTX 590 or it's simply not meant for editing. I trust the Quadro's out of experience. Not sure about the new generation cards in dynamics for gaming and editing, but I prefer a non gaming card tbh, and I'm pretty sure Apple is trying to target a new generation of gamers as well and follow the PC boat.