Hi Mark, I use a 2012 i5 (2.5Ghz) Mac Mini with 10gb ram and the stock 500gb hdd. I use it for editing Nikon NEF files from a D600 (24mp) using Lightroom and Photoshop. I also use it to edit HD video from the D600 using Final Cut Pro X.
Photoshop performance - I have no issues with this at all, and the times I've created large composites (like you, not really above 500mb) it has handled them without issue.
Lightroom performance - from what I've read Lightroom likes a powerful processor, and doesn't utilise multi cored processors above 4 cores particularly well (i.e. there is little performance gain going from 4 cores to 6 or 8 etc. especially when weighed against the extra cost). The gain to be had from the faster processor is in the creation of previews, rendering the file when viewing the raw in the develop module (it takes my machine about 2s to display the image sharp, which can be frustrating with a lot of images to edit), and in exporting the files.
Lightroom apparently only utilises the GPU in the Develop module. I notice next to no lag when applying a change meaning once the image has been rendered after the aforementioned 2s wait, making adjustments to the image runs smoothly. My machine has Intel HD4000 graphics. I also use the Nik suite of plugins. Creating the initial TIFF takes a while (perhaps slowed by the hdd, the files created are big). Once the file and plugin are loaded, making adjustments is quick once again, and saving the file back to Lightoom is once again a bit slow. I've heard that the Nik plugins are GPU aware so once the file and plugin are loaded then performance may well be quicker (inc. saving) with a better GPU.
Final Cut Pro X - editing the footage is smooth. Scrolling along the edit line and having the waveforms and thumbnails render is laggy, but useable. I wouldn't want to use my machine on a daily basis for editing, let a lone for large projects (I use it for up to 10min sequences). Rendering of some transitions can take a while. Exporting of footage is quick. A friend has a quad core i5 iMac and it runs everything in FCPX a lot more quickly. Quad cores definitely makes a difference!
I plan to up the ram to the maximum of 16gb at some point.
Matched pairs apparently makes a big difference, especially for the integrated graphics. I also want to install a 1Tb SSD and keep the 500Gb in the machine to store my music collection. The SSD will allow the machine to boot and load programs more quickly, I'm not sure if it will significantly improve performance once using any particular program.
It would seem we live quite close to each other, I'm in Ealing W. London. My wife's family live in Oxford so we regularly whizz by High Wycombe on the M40.
www.charleshenderson.co.uk
