I definitely value quietness, but also appreciate speed for exporting 36mp images from Lightroom. I tested last night and general browsing of images kicked the fans up on my i7. I'm ok with fans when its exporting as I can walk away then but while I'm browsing images? Nah that seems too much.
So I'll send this i7 back and get an i5. I'm not down with all these 7600 terms. I can only go with whats listed on Apple's site. Is the 3.8GHz i5 going to be ok? Good balance of speed and cooling?
My concern is that the i7 is noticeably smoother than my old 2012 i5 and I don't want to lose that. It's nice having a computer that doesn't feel sluggish when doing the simple things like swiping Spaces or opening a Safari tab.
For those who don't know, his i5 is this one:
http://www.everymac.com/systems/app...-i5-3.2-27-inch-aluminum-late-2012-specs.html
There are a number of factors here, including:
You have a much faster CPU. Your old one was a Core i5-3470
You have a much faster GPU. Your old one was an nVidia GeForce GTX 675MX (or 680MX)
You have either a Fusion drive or a full-on SSD. Not sure which. I don't think you said, but your old one either had a hard drive or a Fusion drive.
So without you telling us all the details, it's hard for people know for sure why the new machine is better. For maximum responsiveness though, you'll want a fast CPU and an internal SSD (not Fusion drive).
As mentioned earlier in the thread, here are the chip specs:
i7-7700K: 4.2 GHz, with Turbo Boost up to 4.5/4.4/4.4 GHz. HyperThreading support. 91 Watt TDP. Fastest by far in multi-threaded applications, but may be only a little bit faster in single-threaded applications.
i5-7600K: 3.8 GHz, with Turbo Boost up to 4.2/4.1/4.0 GHz. No HyperThreading support. 91 Watt TDP, but runs cooler than i7-7700K.
i5-7600: 3.5 GHz, with Turbo Boost up to 4.1/4.0/3.9 GHz. No HyperThreading support. 65 Watt TDP. Performance not far off 7600K.
i5-7500: 3.4 GHz, with Turbo Boost up to 3.8/3.7/3.6 GHz. No HyperThreading suport. 65 Watt TDP. Coolest of the bunch, but also the slowest.
I went with the i7-7700K, and it was silent for the vast majority of my usage, but not 100% of my usage. I decided to chase silence and sent it back and ordered the i5-7600. With a Radeon 575 and i5-7600 and SSD, I'm not really concerned about OS smoothness, although I wonder how well these new iMacs handle dual 5K screens, if I should decide to get a 5K external screen later. The 575 is faster than the 2015's top-of-the-line GPU though IIRC, even if it isn't as fast as the new 580.