I am purchasing a 27" iMac and would be grateful for advice about which processor to buy. Compared with the i7, I know the i5's clock speed is slower (3.2 vs 4.0 GHz) and it does not support hyperthreading, but is there a significant increase in performance in Photoshop? I will invest in memory (32 GB) and a fast drive. Thanks!
You likely won't see a performance difference in Photoshop, but it would make a significant difference for Premiere Pro or After Effects.