Re: Is the iMac 5K 27" powerful enough to edit 4K video?

I bought a new iMac (MK462LL/A) computer. The specs are:
27" Retina 5K IPS Display
5120 x 2880 Screen Resolution
3.2 GHz Intel Core i5 (Skylake)
8GB of 1867 MHz DDR3 RAM
1TB 7200 rpm HDD
AMD Radeon R9 M380 GPU (2GB GDDR5)
802.11ac Wi-Fi, Bluetooth 4.0
Thunderbolt 2 + USB 3.0
Magic Keyboard & Magic Mouse 2 Included
Mac OS X 10.11 El Capitan
I plan to upgrade the RAM to 32GB myself.
I want to edit XAVC S, 4K video shot with my Sony FDR-AX100 camcorder using Final Cut Pro X. I really don't want to spend the extra money for the i7 processor model. Has anyone used this same or similar model iMac to edit 4K video? If so, did it work well? I don't mind if the rendering time takes longer, I just don't want a lot of lagging or choppy video play when editing.
I have not taken the computer out of the box yet, as I may return it if I find out the specs are not up to editing 4K.

Hi Danny,

The GPU is not only important for increased rendering speed. A better GPU also presents a big benefit when you want to work natively with highly compressed footage such as XAVC S. When you play video, your computer needs to de-compress every frame in realtime so you can see the full quality playing. That is done by the GPU. When you work with an edit-friendly full-frame codec such as ProRes 422, the GPU does not need to work hard to decompress the video frames on the fly. But when you work natively with very compressed XAVC, AVCHD or H.264 video, the GPU will have to work much harder.

If you optimize the XAVC 4K footage to ProRes before editing, you won't have any issues at all. But wether an i5 is fast enough to decode native 4K XAVC on the fly (while also handling many other processes), without any hickups, I don't know. I do know the 5K 27" iMac with an i7 handles any given native video you throw at it very well, I have a few ones of these. But I cannot guarantee that the i5 is up to the same task. I think you should test this first.

Best wishes,

Ronny

Update:
I exchanged to the next step up with a better graphics card and a 2TB Fusion hard drive.

27" Retina 5K Display with IPS Technology
Intel Core i5 Processor 3.3GHz
Mac OS X 10.11 El Capitan
8GB DDR3-1867 RAM
2TB Fusion Drive
AMD Radeon R9 M395
SDXC Card Slot
10/100/1000 Network
802.11ac Wireless
Bluetooth 4.0
I am going to upgrade to 32GB of RAM and try editing my 4K videos with FCP-X. I have 15 days to return it if I need to. I will report back here with my review of how well this system works for me.
Thanks for the two replies so far!

Hello everyone. I have a similar question to the posed above, and looking for help.

I am looking to make the jump to buying the brand new IMAC 27inch with the 5k Retina display to replace my original IMAC that I purchased back in 2009. I am pretty set on a machine, but have a few questions to be budget conscious.

Let me start off by saying that I am still running Final Cut Studio 3 and have not upgraded to FCPX. I don't really intend to get FCPX as I am very pleased with Studio 3. The only draw back is that I lost Motion when I upgraded to the Sierra OS

I mainly work with full HD footage, and haven't done any 4K work yet.


RAM vs GRAPHICS CARD....
should I stay with 16 Gigs of RAM or should I invest in the 32 gigs?
Should I get the AMD RADEON R9 M395 with 2 gigs of video memory or invest in the M395X with 4 gigs of memory?
If I can only have one or the other, which should I invest the most money in? Graphics card or RAM?

I will be investing in the 4.0 GHZ Intel Quad Core I7 Turbo Boost Processor and 1TB fusion drive.

Any help on this matter would be apprecaited. Thank you!!

Hi CEOFAE
If you are getting the 27" iMac the RAM is user upgradable and buying from a reputable seller will most likely save you some money and can be later.
The CPU/GPU is not user upgradable so I suggest you get the best you can afford and the i7 has several advantages over the i5.
If you are staying in HD only and do not plan on every editing in 4K or greater, then there are far fewer demands on the computer. 4K can be taxing on the system especially if you have multiple streams or lots of heavy processor intensive effects. Some of the new codecs are processor intensive during transcoding.
FCPS does not take full advantage of the latest hyper threading and multicore processing so legacy FCP is much slower in rendering effects processing. I highly recommend FCPX not only for faster processing, but faster editing and metadata management. Takes some getting used to and you really have to forget what you learned in legacy, but once you try it there really is no wanting to go back. Free 30 day trial so set aside some time, view some free tutorials and try it.

As to Motion, Motion is a free standing program so if you purchase Motion 5, you can use it with FCPStudio. Other programs within the suite are deprecated and may not work fully or at all. Motion 5 is a big improvement over 4 IMHO. It is the basis of all effects and most plug-ins in FCPX.

Hope this helps, Greg

Added to which, you will need some hefty external thunderbolt storage.

Gentlemen,

We are buying as well -- and our question is -- is a top of the line iMac enough to handle multiple streams of 4K (looking five years down the road) -- or would we better off future-proofing with a MacPro?

We're thinking we'll be inputting video from two 4K cameras -- and some 4K drone footage.

Money is a consideration -- but functionality paramount.

That said, we have seen convincing arguments googling -- that indicate the best iMac one can buy with a the 5K screen is enough?

Thank you,
JR

I would not buy a Mac Pro right now. It hasn't been updated in 3 years and as such is obsolete, especially for the high $$$ they are STILL selling it for. If you can get one at a much lower cost, sure go for it. I'd wait for a new Mac Pro if they even bother to make one. But that might be another 2 or 3 years away. Apple doesn't seem to care much about it's pro customers.

Totally agree with Joe about not buying a new MacPro now. If a MacPro is on your radar, I would wait until September before making any decisions.

Actually we are testing a maxed out 27" 5K iMac for 4K multicam editing. The computer certainly is powerful enough to handle many streams of 4K. The real bottleneck is the media drive.

- Played from the internal drive: up to 4 streams ProRes 422 4K at Better Performance "works", but not ideal. There is a noticeable latency because the drive cannot keep up with reading the media and handling the OS and applications at the same time.

- Played from an external Thunderbolt2 Pegasus RAID (600 MB/s): up to 6 streams ProRes 422 4K without any issues. At Best Quality there sometimes is a lag between pause and playback. At Better Performance everything is smooth.

- Played from a Lumaforge Jellyfish 10 GigE desktop shared storage system (1034 MB/s per client): 16 streams ProRes 422 HQ 4K at Best Quality without any problems at. Playback without any lag on un-rendered timelines.

We are going to do some more testing with native highly compressed 4K as well, but that should not be a real problem for the i7 processor as long as you use fast enough drives.

Best wishes,

Ronny

Joe/Ronnie -- So an i7 would seem to be the way to go for us -- which saves a chunk of money -- not to mention we wouldn't need a monitor.
Not having set up a raid before -- does that require just one of the two thunderbolt 2 ports out of the iMac?
Big help, thank you.
JR

JR,

Just one Thunderbolt port to hook up a RAID. With my Pegasus RAID there is a second Thunderbolt port on the back of the RAID for a pas through (to continue the Thunderbolt chain).

--ken

thanks ken.

You did not mention what codec your 4k video was shot with.

I think that the speed of the drive holding the 4k is very important. If you want to edit 4k then a RAID would be a good idea. Having said that you can edit with a fast standard drive like a FireWire 800 but it may stutter a bit on playback, particularly if you have added filters.

You can set the playback quality in the Viewer Options drop-down menu if you are having playback issues.
Better Quality or better Performance.

FCP X does offer Proxy editing which will run 4k just fine on the 27" iMac.

I just worked with some 4k footage (better quality) shot with the JVC 300 using my Pegasus RAID and also from a Thunderbolt standard single drive, the video played back properly from both drives. I'm using a 4 year old 27" iMac.

My 2 cents

--ken

Danny,

Thanks for starting this thread - I was interested to find out your experience with your machine - editing and playback smooth? I was thinking about getting the maxed out imac 5K with the i7 processor and the 4gb AMD M395X but with 16GB RAM for editing XAVCS 60-150mbps 4K video, with footage of about 60-120 minutes in length.

Thanks

If your Mac computer is not powerful enough, you can create a Proxy media which will significantly enhances playback performance in Final Cut Pro X’s viewer by lowering the video quality to one-half resolution. In Final Cut Pro, proxy media is converted to Apple’s ProRes 422 Proxy format.

You can directly create Proxy Media with FCP X. There are multiple ways to create Proxy media in Final Cut Pro X: You can do so upon initial media import, or you can do so after media is imported.