FCPX performance tests: 2015 vs 2017 iMac 27 vs 12-core Mac Pro D700

I just tested FCPX 10.3.4 on a 2015 vs 2017 top-spec iMac 27. The 2017 is much faster in some FCPX workflows, far more than synthetic benchmarks would indicate. It is about 2x faster to transcode 4k H264 long GOP to ProRes proxy, and about 2x faster exporting to 4k H264.

When editing 4k H264 long GOP on a timeline without proxy or optimized media, the viewer frame rate is much faster -- it's hard to quantify and it likely varies with the exact codec variant, but it seems about 3x faster. For the first time on any hardware or editing software I've tested, it's fast enough to edit single camera 4k H264 long GOP without proxy. Editing two-camera 4k H264 multicam on the 2017 is faster than single-cam on the 2015 model.

Compared to the 12-core D700 nMP I tested recently, the 2017 iMac feels much faster on H264 workflows. The nMP still has an advantage if doing ProRes acquisition (so you don't have to transcode) and if maintaining an all-ProRes workflow.

Ironically (despite its faster GPU) the 2017 iMac isn't that much faster than the 2015 on several FCPX effects I tested.

Under heavy CPU load the cooling fan on the 2017 iMac does spin up to 2700 rpm quicker, but the CPU temps never get about about 70C during FCPX transcoding. However for some workloads it is doing twice the throughput, so for me that's an OK tradeoff. My desk is stacked with spinning Thunderbolt drive arrays and they all make noise. For someone doing sustained high-CPU work with only SSD storage in a quiet room, it might bother them.

Other tests:

Neat Video 4.5.5 on 31 sec clip of 4k XAVC-S from Sony A7RII (each optimized using Neat Video config utility for optimal CPU/GPU split):

2013 12-core Mac Pro D700: 6 min 58 sec
2015 iMac 27 i7: 9 min 7 sec
2017 iMac 27 i7: 8 min 3 sec

Digital Anarchy flicker reduction on 12-sec H264 4k from DJI Phantom 4 Pro:

2013 12-core Mac Pro D700: 9 min 6 sec
2015 iMac 27 i7: 9 min 15 sec
2017 iMac 27 i7: 7 min 38 sec

BruceX FCPX benchmark (each average of two runs)

2013 12-core Mac Pro D700: 17.0 sec
2015 iMac 27 i7: 25.8 sec
2017 iMac 27: 15.8 sec

FCPX sharpen effect on 31 sec H264 4k XAVC-S clip, timeline render:

2013 12-core Mac Pro D700: 27.7 sec
Using ProRes optimized media: 12.1 sec

2015 iMac 27: 21.2 sec
2015 iMac 27 ProRes: 24 sec
2017 iMac 27: 20.3 sec
2017 iMac 27 ProRes: 23.8 sec

FCPX aged film effect on 31 sec H264 4k XAVC-S clip, timeline render:

2013 12-core Mac Pro D700: 30.45 sec
Using ProRes optimized: 21.8 sec

2015 iMac 27: 35.3 sec
2015 iMac 27 ProRes: 47.3 sec
2017 iMac 27: 29.8 sec
2017 iMac 27 ProRes: 37.8 sec

joema wrote: I just tested FCPX 10.3.4 on a 2015 vs 2017 top-spec iMac 27. The 2017 is much faster in some FCPX workflows, far more than synthetic benchmarks would indicate.

This is why I never pay much attention to those render time comparisons. What counts for me is smooth playback. And of course I am pissed now. My 2015 iMac s just a year old.