New iMac for 4K Video Editing - £2500 Budget

Discussion in 'iMac' started by russkn87, Oct 9, 2018.

  1. russkn87 macrumors regular


    Apr 24, 2015
    Kent, UK
    Hey everyone,

    I'm in the market for a new iMac 27", with a budget of around £2,500. It will be used for video editing in Final Cut Pro X. Video footage will be from UAVs & a Lumix GH5 in 4K.

    I'm patiently waiting for the 2018 to be announced, but in the meantime trying to figure out what the best options would be. I'm currently using a late 2012 iMac which is still good as new - but my 512MB graphics can't quite handle the 4K 60fps footage as well as I'd like

    - Do I need an SSD? I read that SSD is the most important thing to opt for, but on my budget I will only be able to opt for the smaller size. I guess I'd have to get an external SSD or HDD to work from, as my camera usually has 200GB footage after a day of shooting weddings. I don't really want to have loads of externals plugged in, but at the same time, backing up my 200GB+ of footage after a long day needs to be practical and reliable.

    - Do I need to go for the i7 over the i5?

    I know I need the 8GB graphics, so that's fine, and I'll go for 8GB RAM and add more myself at a later date.

    So it's just the question about the processor and then the SSD or Fusion drive that's my main concern for video editing.

    On another note... Apple, hurry up and announce the 2018 iMac!

  2. sublunar macrumors 6502a

    Jun 23, 2007
    The i7 is going to be faster but on a £/performance basis (with a dollop of concern over heat) I might suggest sticking with the i5 if you have a limit on your budget. 6 cores is more than enough if you have an eye on the budget, I'd argue that on a limited budget the i7 should be the first to go.

    RAM will be the most important and if the RAM isn't accessible (because Apple will have imitated the iMac Pro and done away with the easy to upgrade RAM door) and is priced at Apple prices then prepare to be shocked at the prices. Save a lot of your budget for as much RAM as you can get. 16Gb minimum. Do not mess around with 8Gb initially.

    GPU is also important but Apple do charge accordingly. If there's a lot of 4k footage going on then the notional AMD Pro 580X might be the one to go for there.

    Internal SSD for boot drive will be a must in my opinion, many folks insist on sticking with SSD only and I agree. External storage can be added later via Thunderbolt or USB and if you're editing footage then external TB3 SSDs could be the way to go.

    It's also worth trawling some of the big third party retailers to see if they do away with stock models of the 2017 27" iMacs in case of deals that you can add your own RAM to later. The top SKU current 2017 iMac off the shelf might do you nicely for instance if a few hundred quid were lopped off the price.
  3. droog, Oct 9, 2018
    Last edited: Oct 9, 2018

    droog Suspended


    Apr 10, 2018
    LoL. Don't get an i5 for video editing. It's probably the worst decision you could make. Seriously. Don't do it. You need all the cache, cores and hz you can get. Macs have a premium attached to them. Pay up or move along. Settling for less is not an option and you will regret it. Your best bet is the refurb store or second hand. You seem to be 500 off of target or so with your current budget.
  4. russkn87 thread starter macrumors regular


    Apr 24, 2015
    Kent, UK
    Thank you so much for taking the time to give me such a detailed reply! I really appreciate it.
  5. Malus120 macrumors 6502

    Jun 28, 2002
    Before diving into the specifics, I think it would be helpful, both for those of us trying to give you advice, and for you yourself, to specify exactly where/how/what you mean when you say your 2012 iMac "can't quite handle the 4K 60fps footage as well as I'd like." Is the bottleneck really your GPU, or could it be your storage (do you have an SSD in your 2012 iMac?). How is the CPU holding up for your workload? Do you feel like you would benefit from more/faster cores or not so much? Is ram a limiting factor? To put it another way, what kinds of operations in FCPX are you looking to speed up?

    The short answer here is yes, you really need/want an SSD for video editing (particularly 4K,) in fact you don't just want an SSD, you ideally want the fastest one you can afford. The longer answer is that while an internal Apple SSD (ideally a large one) would be ideal, if cost is an issue, an external SSD connected via USB C or Thunderbolt 3 would also work, and given how fast storage prices are falling, could likely save you a lot of money (I ended up doing this with my MBP, picked up a USB-C 500GB SSD for around $110).

    It really depends on your own needs / use case, and I recommend you look at benchmarks of the iMac Pro vs the current Retina iMac to give you an idea of how FCPX scales across cores performance wise. It will also depend whether the refresh uses 8th generation chips (so i5 is 6C/6T while i7 is 6C/12T) or "9th" generation chips (i5 is 6C/6T / i7 is 8C/8T). IF Apple goes with 9th gen then I'd say go with the i7 if you can, but if its 8th gen I'd say you'll have to decide how much hyper threading is worth to you. As much as it will piss people off I wouldn't be surprised if we see 8th gen, given that Intel hasn't given shipping estimates for 9th gen yet and it would really eat into iMac Pro territory CPU wise.

    External GPU support means that you could actually just stick with the base GPU option (even a 570 class GPU is way faster than the GPU in your 2012 iMac) and then add an eGPU down the line if need be. As for RAM, unless its soldered in like in the iMac Pro (don't do it Apple...), then yes, upgrading the ram yourself makes sense.

    I'd suggest you do a bit more research on your own needs and publicly available benchmarks of existing machines. That said, I'd say that, unless RAM is soldered in (in which case it unfortunately becomes your FIRST priority), it's a question of how much flash storage you can afford (and whether you choose internal vs external), and then how much of your budget is left over after that. If you're still within budget or can go over a bit then I'd say CPU>GPU (as GPU can be "upgraded" later).
  6. Pad J macrumors newbie

    Oct 10, 2018
    Related question: I have a 2011 iMac 27" which is due for replacement. Do I go for a 5K 27" iMac or a retina (4K) 21.5" and add an external 4k 21.5" display? I don't need the huge single space, but definitely more screen space than a single 21.5 display supplies.
    As I see it, an additional advantage of the 4k external display is that i can disconnect it from the iMac and connect my (travel) Macbook to it. Or am I getting confused?
    advice please
  7. Malus120 macrumors 6502

    Jun 28, 2002
    While it will in part depend on what the 2018 refresh brings, the 21" model is, in general a worse deal in terms of price/performance, along with having semi-non upgradable memory. I would suggest that you would be better served by focusing on deciding what specifications, and thereby what model(s), will best meet your needs without getting hung up on display size.

    For reference, I currently have dual 4K 27" monitors and while its a great setup, I think I'd prefer the 5K 27" screen vs a 21.5" 4K screen (two small even at Retina 1080 IMHO) with an additional 4K screen (especially if the other screen was a different size). I also definitely don't think it's worth paying the "small 4K display premium" just to get a display that roughly matches the 21.5" iMac in size.
  8. Fishrrman macrumors P6


    Feb 20, 2009
    Get a 27" i7 (or at least a higher-spec i5).

    Get 8gb of RAM from Apple and add more later on your own (cheaper).

    You MUST have an SSD. I'd suggest 512gb (and add external USB3 storage if required, either SSD or HDD). If you don't get an SSD, my fearless prediction is that you are going to be very unhappy with your purchase.
  9. Samuelsan2001 macrumors 604

    Oct 24, 2013
    To be honest until the new ones are released a 15 inch MBP with an external screen is a better bet.
  10. russkn87 thread starter macrumors regular


    Apr 24, 2015
    Kent, UK
    Thanks for your help everyone. I'm going to try and stretch my budget a bit - I think I'm going to sit on the i7, 1TB SSD, 8GB iMac in my basket for a couple of weeks to see if the rumours progress for the 2018 models. I will be completely bummed if they update them with non-upgradable RAM though!

    For video editing, the main issue I have is slow rendering the output file (5 hours at the moment for a 1080p (from 4K)!!) and also adding things like light leaks, colour grading - they seem to slow everything riiiight down. I'd really like to be able to output in 4K, it just takes so long at the moment.
  11. joema2 macrumors 68000


    Sep 3, 2013

    I've owned and done extensive FCPX work on a 2012, 2013, 2015 and now a 2017 i7 iMac 27, plus a 2017 10-core iMac Pro.

    H264 4k is difficult to edit on almost any hardware or software. In general it requires proxies for really smooth editing performance. Once those are generated, FCPX on almost any Mac will be fast -- even a 2013 MacBook Air.

    The data rate of 8-bit 4:2:0 4k H264 from a drone or GH5 isn't that high. It's not remotely an I/O bandwidth issue. It primarily a CPU issue to decode and encode the codec, plus partially a GPU issue for processing certain effects -- but only effects which are GPU accelerated.

    The Kaby Lake CPU in the 2017 iMac is much faster on H264 than a similarly-equipped 2015 iMac. This is likely due to the updated Quick Sync logic on the Kaby Lake CPU. In my tests it exports about 2x faster and timeline operations on camera-native 4k H264 are much faster. So going from a 2012 to a 2017 iMac you will see a vast improvement on 4k H264.

    For effects, the RP 580 GPU on the 2017 iMac is much faster than any option on the 2012, so that also helps.

    I've edited extremely large documentaries on a 2013 i7 iMac 27 with a 3TB Fusion Drive, although the media was on an external Thunderbolt array. The 2 and 3TB Fusion Drives work fine, and my side-by-side tests with an 2015 i7 iMac 27 with 1TB SSD didn't show significant difference in boot time or app startup time.

    That said, it's probably best to get an SSD iMac because you eventually run out of space even on a 3TB Fusion Drive. Also you generally want your media external. If it's inevitable that media will be external, then getting a (say) 512GB SSD makes sense. Also on any rotational drive (inc'l Fusion) you must reserve a significant % of free space else performance will degrade. E.g, on a 2TB Fusion Drive I wouldn't use more than about 1.2-1.5TB. This erodes the superficial price per megabyte advantage of Fusion Drive. On SSD performance will be pretty good up to 98 or 99%, so suddenly the 2TB Fusion Drive space advantage over a 1TB SSD is minimal. It then only has a price advantage.

    A 2017 iMac 27 with 1TB SSD has the I/O performance to put everything on the system drive, just not the space. You think "all I'm shooting is 200GB", but you must add cache, proxies, bits of previous projects, etc. If you have an assistant shooting 45 megapixel raw stills, that takes lots of space also, esp. if processed through a plugin as TIFFs.

    Everything must be backed up, whether internal SSD, rotational drives or external RAID drives. So part of the budgeting and planning process must include space for backups.

    An i7 2017 iMac would be a big step up in FCPX editing performance on 4k H264 material vs your 2012 model. However we might be so close to the release of a 2018 update, it's best to wait if you can.
  12. cynics macrumors G4

    Jan 8, 2012
    Your work flow will have a bottleneck somewhere just by its vary nature (ex export times will never be instant). Assuming that the RAM is upgradable that machine will suit you will for quite a while.

    Although a bit more expensive I would consider 16gb of RAM so you can just job too 32gb if the need arrises without the need to discard the shipped with RAM. Although 24gb is likely be adequate.

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11 October 9, 2018