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2017 iMac Pro: RAW to JPEG

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See the MPG recommendations for iMac Pro, backup, peripherals. Not sure which Mac to get or how to configure it? Consult with MPG.

These tests assess Photoshop raw-file conversion performance via the Adobe Camera Raw Dialog batch processing feature.

The following camera raw file formats were tested across 7 different machines:

  • 50-megapixel Hasselblad X1D XFR
  • 50-megapixel Fujifilm GFX RAF
  • 45-megapixel Nikon D850 NEF
  • 42-megapixel Sony A7R III ARW

Variations in processing speed accrue from the GPU the number of CPU cores of course, but it is as dependent on the raw format as anything.

Some file formats are inherently speedier or slower: for example, the Fujifilm GFX uses a lossless compressed raw format that forces single-threaded decoding. Nikon’s NEF format is also lossless compressed, but a bit faster to decompress. The Hasselblad X1D does not compress its files. Sony uncompressed raw requires no decompression and its compressed raw format is extremely fast to decompress.

Summary: the iMac Pro (all models) fails to impress and the 2017 iMac 5K represents tremendous value.

SSD upgrade that takes full advantage of APFS


Sony’s ARW raw file format (compressed or uncompressed) allows for very fast decoding, so Sony raw files process faster than any other format, with uncompressed files a huge ~86MB each but converting 6% faster. This is about as fast as it gets for raw conversion.

  • The 2017 iMac 5K puts in a valiant performance for a 4-core CPU, but it lags the 8-core iMac Pro by about 21% and the 10-core Vega 64 Mac Pro by about 31%. But unless large batches of files are being processed, it’s still very fast.
  • iMac Pro Vega 56 vs Vega 64 is trivially different in speed, so upgrading to Vega 64 is a waste of money for Sony raw conversion.
  • 8-core iMac Pro is only about 5% slower than the 10-core Mac Pro.
Photoshop RAW to JPEG batch processing speed: Sony A7R III
2017 iMac Pro vs others

RAW to JPEG: Nikon D850

Nikon’s lossless-compressed NEF raw file format saves a lot of file space with only a modest hit to decoding speed.

  • The 2017 iMac 5K lags the 8-core iMac Pro by about 25% and the 10-core Vega 64 Mac Pro by about 25%, the 10-ccore Vega 56 Mac Pro by about 24%, and the the 10-core Vega 64 iMac Pro by about 34%.
  • The 8-core iMac Pro and 10-core Mac Pro show now meaningful difference (both have the Vega 56 GPU)!
  • The iMac Pro 10-core Vega 64 lags the iMac Pro 10-core Vega 56 by 8%.
Photoshop RAW to JPEG batch processing speed:Nikon D850
2017 iMac Pro vs others

RAW to JPEG: Fujifilm GFX

Fujifilm’s lossless-compressed RAF raw file format is very slow to decode and entails a substantial performance hit (compare to the 45-megapixel Nikon D850).

The 2017 iMac 5K beats ALL the iMac Pro models! So much for a 'pro' computer, since the GFX is a professional medium format camera.

The win can be explained fairly simply: the base clock speed of the 2017 iMac 5K is 4.2 GHz, with Turbo Boost to 4.5 GHz. Since the GFX RAF raw file format entails a single thread/core for decoding the raw file format, the CPU that can run a core or two very fast wins.

The foregoing has implications for studio shooters: one is just as well off with 2017 iMac 5K.

Photoshop RAW to JPEG batch processing speed: Fujifilm GFX
2017 iMac Pro vs others

RAW to JPEG: Hasselblad X1D

Hasselblad’s uncompressed 3FR raw file format is not compressed, but for whatever reason Photoshop’s Adobe Camera Raw takes 'forever' to process its raw files.

The 2017 iMac 5K puts in an amazing showing, trailing the iMac Pro 10-core Vega 56 by only 14%. Not too impressive for an iMac Pro costing $4K more. And the iMac 5K trails the iMac Pro 8-core Vega 56 by only 5%—wow!

As elsewhere, the Vega 64 GPU ekes out a small advantage over the Vega 56 CPU on the two 10-core iMac Pro systems—a paltry 3.6% which is not even perceptible.

Photoshop RAW to JPEG batch processing speed: Hasselblad X1D
2017 iMac Pro vs others

Recommended Items for iMac Pro and iMac 5K

See the recommendations page for details on why these items are recommended.

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