[Pao|o]

Given these parameters do I need 2GB of VRAM or will 1GB do on the 27-inch iMac Core i7?

1. I am a heavy user of Aperture 3 and Final Cut Pro.
2. I have a 27-inch Dell U2711 that I intend to attach to the 27-inch iMac. That's two 2560x1440 resolution screens.
3. I may purchase another 27-inch Dell U2711 to attach to the 2nd Thunderbolt port. That's three 2560x1440 resolution screens.

Once the iMac arrives I intend to swap out the standard 4GB with 16GB of RAM.

[mduell]

Usually I tell everyone to not even think about VRAM, but for a heavy Aperture user I'd say get the 2GB.