iMac Pro or next year’s Mac Pro?

[Joe Marler]

I have a 10-core Vega 64 iMac Pro. It’s very quiet — the fans rarely spin up even under sustained FCPX transcoding. It has a UHS-II SD card reader, 10 gig ethernet and lots of ports on the back.

I’ve seen tests showing it’s much faster on an all-ProRes or RED RAW workflow than a top iMac.

However most of my acquisition and editing is 4k H264, and the picture is more mixed. It is much faster on this media than the 2013 12-core D700 trash can. So it’s a good upgrade for anybody with aging Mac Pros.

While Xeon does not have Quick Sync, FCPX is apparently using AMD’s UVD/VCE hardware transcoding acceleration. However in some tests (at least on this version of FCPX and macOS) it’s not faster than an i7 2017 iMac. When editing a 4k H264 timeline it is subjectively no quicker or more responsive than the 2017 iMac. It cannot smoothly edit multicam 4k H264 without proxies, no different than the 2017 iMac.

Below are some tests on my 10-core Vega 64 iMac Pro vs. 2017 i7 iMac 27 (min:sec)

iMac Pro export 60 sec 4k/29.97 H264 to 4k H264 Fast Encode: 00:45
2017 iMac export 60 sec 4k/29.97 H264 to 4k H264 Fast Encode: 00:38

iMac Pro export 60 sec 4k/29.97 H264 to 4k H264 Best Quality: 01:25
2017 iMac export 60 sec 4k/29.97 H264 to 4k H264 Best Quality: 01:11

iMac Pro export 60 sec 4k/29.97 H264 to 4k ProRes 422: 00:23
2017 iMac export 60 sec 4k/29.97 H264 to 4k ProRes 422: 00:36

iMac Pro export 60 sec 4k/29.97 ProRes 422 to 4k ProRes 422: 00:10
2017 iMac export 60 sec 4k/29.97 ProRes 422 to 4k ProRes 422: 00:13

Imac Pro create optimized media from 06:09 4k/29.97 H264: 02:05
2017 iMac create optimized media from 06:09 4k/29.97 H264: 03:40

(I don’t have the numbers for creating proxies from 4k H264 but the iMac Pro is a little slower than the iMac)

iMac Pro export 60 sec 4k/29.97 ProRes to 4k H265 8-bit: 00:43
2017 iMac export 60 sec 4k/29.97 ProRes 422 to 4k H265 8-bit: 02:16

iMac Pro export 60 sec 4k/29.97 ProRes to 4k H265 10-bit: 22:02
2017 iMac export 60 sec 4k/29.97 ProRes 422 to 4k H265 10-bit: 32:47

Neat Video 4.7, optimal config for iMac and iMac Pro, 4k/29.97 H264:
iMac Pro: 5.29 frames/sec
2017 iMac: 2.76 frames/sec

Digital Anarch Flicker Free on 10 sec of 4k/29.97 H264:
iMac Pro: 05:09
2017 iMac: 06:31

Imagenomic Portraiture skin processing on 10 sec 4k/29.97 H264:
iMac Pro: 01:07
2017 iMac: 01:10

Comments:

– FCPX is obviously not using hardware acceleration for HEVC/H265 10-bit export on either iMac Pro or iMac
– The 2017 top-spec iMac is a little faster at 4k H264 export than the 10-core Vega64 iMac Pro
– On effects, the iMac Pro performance advantage varies widely depending on the specific effect
– The iMac Pro is faster than the iMac at export from 4k H264 to 4k ProRes
– The iMac Pro is faster than the iMac on an all-ProRes workflow

iMac Pro: 10-core Vega64 iMac Pro, 64GB RAM, 2TB SSD, macOS 10.13.3, FCPX 10.4
2017 iMac: 4.2Ghz i7-7700K, 32GB RAM, Radeon Pro 580, 2TB SSD, macOS 10.12.6, FCPX 10.3.4
Camera and codec: Sony A7R2, XAVC-S, 4k/29.97 H264 100 mbps 8-bit 4:2:0

[Oliver Peters]

Our shop has 3 of the same model as Joe. Great machine, very happy. Our results are similar. Here’s a blog post I wrote testing them out.

https://digitalfilms.wordpress.com/2018/01/06/putting-apples-imac-pro-through-the-paces/

– Oliver

Oliver Peters – oliverpeters.com