Which iMac 2017 for editing and grading?

[joema]

2 hours ago, Fredrik Lyhne said:

....It seems I can do just fine with this MBP, but when the iMac is twice as fast for the same money it's very tempting....

Just keep in mind the 2017 iMac 27 i7 is twice as fast as a 2016 MBP or 2015 iMac 27 ONLY on *some* things -- specifically transcoding H264 to ProRes proxy. Considering that's a very time-consuming part of many H264 4k workflows, that's really useful. It's also limited to FCPX; the performance difference varies with each software.

The 2017 iMac 27 i7 is also about 2x as fast (vs a 2015 iMac i7 or a 2016 MBP i7) on the GPU-oriented BruceX benchmark, but this is also a narrow task. On other GPU-heavy or mixed CPU/GPU tasks like Neat Video, it's usefully faster but not 2x faster.

On a few H264 long GOP 4k codecs I tested, the 2017 iMac 27 i7 seems marginally fast enough to edit single-camera 4k material without transcoding (on FCPX), which is a big improvement from the 2015 iMac 27 i7 or 2016 top-spec MBP. However multicam still requires transcoding to proxy, and if you want to really blitz through the material, then proxy still helps.

If you now or will ever use ProRes or DNxHD acquisition, this picture totally changes. It then becomes less CPU intensive but much more I/O intensive. You usually don't need to transcode in those cases but the data volume and I/O rates increase by 6x, 8x or more.

 

[Fredrik Lyhne]

15 minutes ago, joema said:

Just keep in mind the 2017 iMac 27 i7 is twice as fast as a 2016 MBP or 2015 iMac 27 ONLY on *some* things -- specifically transcoding H264 to ProRes proxy. Considering that's a very time-consuming part of many H264 4k workflows, that's really useful. It's also limited to FCPX; the performance difference varies with each software.

The 2017 iMac 27 i7 is also about 2x as fast (vs a 2015 iMac i7 or a 2016 MBP i7) on the GPU-oriented BruceX benchmark, but this is also a narrow task. On other GPU-heavy or mixed CPU/GPU tasks like Neat Video, it's usefully faster but not 2x faster.

On a few H264 long GOP 4k codecs I tested, the 2017 iMac 27 i7 seems marginally fast enough to edit single-camera 4k material without transcoding (on FCPX), which is a big improvement from the 2015 iMac 27 i7 or 2016 top-spec MBP. However multicam still requires transcoding to proxy, and if you want to really blitz through the material, then proxy still helps.

If you now or will ever use ProRes or DNxHD acquisition, this picture totally changes. It then becomes less CPU intensive but much more I/O intensive. You usually don't need to transcode in those cases but the data volume and I/O rates increase by 6x, 8x or more.

 

Rendering time and transcoding to optimized media is the most important for me, and actually even more important the ability to edit and grade when rendering in real time. I don't do any multi cam work or use neat video and don't think I will use much in the future. 

I only use FCPX and I'm very happy with that. Would like to try the more advanced grading controls in Resolve at some point though, but I have zero interest in Premiere. 

I would love to get a Ninja Inferno at some point but at the same time I don't won't bulk up the GH5. Hopefully the 400 Mbs codec is released within the next few weeks so I can try that on the new MBP as well. 

Keep in mind that I don't make any money on this at the moment, but hopefully we might in a few months time.

[fuzzynormal]

Man, I love how hobbyist and non-pros are equipped way better than me!  --a guy making a living at this stuff.

I don't know.  I find that sort of cool in a way.

[Richard Bugg]

This bloke shows how he bought a mid-tier 2017 iMac, pulled the screen off then replaced the CPU with an Intel i7, added an SSD and 64GB RAM to apparently achieve faster performance than any other 2017 iMac. Perhaps this is the type of hybrid Hackintosh that makes most sense for the DIY handyman.

[jonpais]

1 hour ago, Richard Bugg said:

This bloke shows how he bought a mid-tier 2017 iMac, pulled the screen off then replaced the CPU with an Intel i7, added an SSD and 64GB RAM to apparently achieve faster performance than any other 2017 iMac. Perhaps this is the type of hybrid Hackintosh that makes most sense for the DIY handyman.

This fellow is good! I think he says it performed better in BruceX than the top iMac with the best GPU, which surprised me a little. 

[Dustin]

Owni a 2012 MBPr that has a known motherboard issue (gets hot way too easy) and gets the job done but is starting to show its age. As much as I love Mac OS I think either a hackintosh or a windows build is in the next year for me. I use premiere pro so I guess I'd have to use intel but the Ryzen chips look sweet! Wouldn't spend more than 1k

[joema]

On 7/18/2017 at 6:41 PM, jonpais said:

This fellow is good! I think he says it performed better in BruceX than the top iMac with the best GPU, which surprised me a little. 

It does not. His BruceX time was 18 sec, mine is 15.8 sec (average of several runs). My 2017 iMac 27 is the 4.2Ghz i7, 32GB, 2TB SSD, RP 580 GPU. 

His GeekBench 4 multi-core CPU score was 20,300, mine was 20,257. His Cinebench R15 CPU score was better at 1102, mine was 936. 

These are the vagaries of benchmarking and don't indicate a clear improvement over a factory top-spec iMac. The BruceX benchmark is especially sensitive to technique. Whether you reboot FCPX or macOS each time, whether you have background rendering off, whether you disable Spotlight indexing and Time Machine before running the benchmark -- all those have an effect. He was either unaware of these or did not mention them.

[Fredrik Lyhne]

Long time no see? I finally got my 4.2GHz, 1TB SSD, 8GB VR. 40GB RAM iMac. It handles the GH5 10 bit files easily and I haven't had the need to transcode anything yet. Thanks guys for all your input, especially @joema and @jonpais