iMac 5K (Late 2015) vs Mac Pro: Convert 50-Megapixel RAW Files to JPEG (Adobe Camera Raw)

Get iMac 5K at B&H Photo and see also MPG’s computer gear wishlist.
See also diglloyd-recommended performance packages for iMac at OWC.

Save money on 32GB or 64GB OWC memory (about $400 savings vs Apple!)

MPG recommends this iMac 5K: 27" Retina 5K Display, 4.0 GHz Intel Core i7 (Skylake), 1TB Flash, 8GB memory, AMD Radeon R9 M395X GPU (4GB GDDR5) + 32GB or 64GB OWC memory.

The two machines tested here are the fastest possible CPUs as of late 2015. The iMac 5K as tested here is well into Mac Pro pricing territory, approaching $4K as configured, though of course it includes the display.

Raw file converson to JPEG

This test is a real-world task relevant to Adobe Photoshop or Adobe Photoshop Lightroom users: convert raw files to JPEG. Disk I/O is not a significant factor, accounting for only a few seconds of a 2+ minute job.

The 1.8% speed difference between 32GB and 64GB memory in the iMac 5K is within the margin of error. However, it was a repeatable finding with no obvious explanation.

The 8 CPU cores of the 3.3 GHz Mac Pro give it an advantage in this test; Photoshop ACR processes multiple raw files simultaneously.

Convert 52 Canon 5DS R 50-megapixel raw flies to max-quality JPEG
late 2015 iMac 5K 4.0 GHz M395X vs Mac Pro