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iMac 5K vs Mac Pro: ACR 36MP Raw to High Quality JPEG
Related: 4K and 5K display, Adobe Camera Raw, computer display, iMac, iMac 5K, Mac Pro, Macs, SSD
Adobe Photoshop CC 20141014.r257
iMac 5K 4.0 GHz, 32GB, 1TB SSD, AMD Radeon R9 M295X 4GB GDDR5 -versus-
2013 Mac Pro 3.3 GHz 8-core, 64GB, 1TB SSD, D700
The two machines tested here are the fastest possible models for this type of work (as of late 2014).
Batch conversion of RAW to JPEG
This test is using Adobe Camera Raw (ACR) in Photoshop CC 2014, but Adobe Lightroom uses the same ACR engine and results should be similar. Both machines with their respective SSDs.
Clearly a fast 8-core machine is the right choice for photographers processing large batches of images (iMac 5K is limited to 4 cores). A six-core is likely to offer similar advantages, and is likely nearly as fast as an 8 core (overhead and I/O means 8 cores are not fully utilized over the batch job).