Which 5k iMac is more suitable for my needs?

Discussion in 'iMac' started by booyah2014, Jan 11, 2016.

  1. booyah2014 macrumors member

    Sep 18, 2014
    In two minds over which 5k iMac to purchase.

    There's a huge price difference between the i5 and the i7 and if I can save money if it will suit my needs then that can't be a bad thing.

    I run a wedding videography business, currently using a very old PC-based system. I currently shoot and edit in 1080p in Premiere Pro with a Canon 5d Mk2. It takes forever to render or pretty much do anything. Typically any project I work on is around 60 minutes long and includes various transitions, effects, multiple audio tracks etc.

    HOWEVER I'm buying a Blackmagic Production Camera 4K (which naturally, shoots in 4K ProRes) next month.

    Although the final resolution of what I make won't be a 4k presentation (I always present in 1080p), I'd like to shoot 4K for cropping and reframing in Final Cut Pro X (I'm moving away from Premiere Pro).

    I also plan to colour grade with DaVinci Resolve 12.

    So looking at this spec:

    5K 27"
    3.2GHz Quad-core i5
    32GB RAM (I have this ready to install)
    256GB Flash storage
    AMD Radeon R9 M390 2GB

    Will this be able to do what I want it to fairly comfortably - DaVinci Resolve 12, FCPX, reframing 4k footage etc?

    Or should I go for the i7 4.0GHz with the M395X for a bigger price?
  2. Samuelsan2001 macrumors 604

    Oct 24, 2013
    Well 4K video editing is where you will see the most benefits of the i7 and the better GPU (other than gaming). That doesn't mean that either machine won't do it absolutely fine but you will see a performance increase from the hyperthreading on the i7 and lower render times for the better GPU. Only you can decide if the better performance will be worth the initial outlay for you. A google search for benchmarks and you tube comparissons may help you decide.
  3. booyah2014 thread starter macrumors member

    Sep 18, 2014
    Thanks. Yes I've heard that hyperthreading on the i7 is a major difference and I'm sure I would notice and benefit from the difference in performance. I am never juggling more than one project so as long as render times for an entire project are bearable (less than 12 hours) for a 60-90 minute 1080P project then I'd be fine.

    Ideally any system would also run smoothly with usage/playback without slow up which I get a lot of on my crappy older PC.
  4. Samuelsan2001 macrumors 604

    Oct 24, 2013
  5. Malus120, Jan 11, 2016
    Last edited: Jan 11, 2016

    Malus120 macrumors 6502

    Jun 28, 2002
    If it's a business expense then I would say it's really quite simple.

    As the above poster mentioned you should look at benchmarks around the web for the apps you use, and then multiply the (potential) time savings and productivity increase by the scale of your business.

    If the i7 and faster GPU will pay for themselves in a short time then obviously you should go for it. If on the other hand the scale of your business is small, the profit margins are thin, and the increased productivity isn't going to result in a noticeable business impact over the life of the machine, then you should probably just save the money and invest it in something that will.

    That said I can attest to the fact that even without hyperthreading for most things the 4Ghz i7 is going to outperform the i5 by a fair margin just on account of the extra raw CPU power available. Anything that can utilize the GPU will also see a nice jump if you go for the 395X as well.

    Honestly from what you said though, it doesn't sound like rendering time is a significant bottleneck for you given you current scale, so maybe you'd be best with the base model?
  6. booyah2014 thread starter macrumors member

    Sep 18, 2014
    Thanks, and you're right I need to weigh up what the right balance is for me. I'm a small business only working on individual projects at a time.

    Just noticed in your signature you have the 2014 5K i7 4.0GHz with the M295X 4GB - how does this hold up for you? Would a refurb one of yours be a good compromise? Apart from the slightly better color reproduction on the 2015 5K, the only major difference is between the M395X and the M295X.

    Perhaps a refurbed 2014 i7 is the way to go..
  7. Malus120, Jan 11, 2016
    Last edited: Jan 11, 2016

    Malus120 macrumors 6502

    Jun 28, 2002
    It's holding up great! One of nicest machines I've ever owned. Honestly the difference between the 2014 and 2015 iMacs is so minimal that if you can get a top end 2014 refurb model for the price of a mid range 2015 I'd suggest going that route with zero hesitation. They really are great machines and the M395X is basically just a rebadged M295X with a slightly higher clock speed, so a high end 2014 model will still wipe the floor with a mid range 2015. That said, be aware that this will probably be a big year as far as GPU upgrades on the iMac side...

    Whichever way you go, DO be aware of the heat issues that the current iMacs (both 2014 and 2015) have when configured with an i7 and Mx95x GPU, and make sure that it's something you can live with (especially if you plan to use the machine beyond the 3 year AppleCare window)
  8. Samuelsan2001 macrumors 604

    Oct 24, 2013
    The major difference id the jump to skylake silicon in the 2015 this is a bit of jump over the haswell architecture in the 2014 and it is much better on heat production making the 2015 cooler and quieter and less likely to throttle the GPU when you are hammering it with a long render, this is also mentioned in the link I posted above.
  9. Malus120 macrumors 6502

    Jun 28, 2002
    While this is true, I would opine that:
    1. If the OP is debating between a mid range 2015 (i5/395) and a full spec 2014 (i7/295X), the full spec 2014 should be significantly faster even when taking throttling and the architectural improvements into account (not to mention that only the i7 in the 2015 model is Skylake)
    2. If the OP is debating between a full spec 2014 and a full spec 2015 then we're back to the issue of RoI, and the OP needs to investigate whether the improvements provided by the 2015 model (which in my opinion are noticeable but not particularly significant) are worth the additional cost.
    3. While the 2015 models improve on the thermal issues faced by the 2014 models, the fundamental design issues (too much heat/throttling/concerns about lifespan) still exist either way, they're just slightly mitigated by the Skylake i7, leading to slightly better results.
  10. Fishrrman macrumors G5


    Feb 20, 2009
    If you're really going to be heavy in 4k video, perhaps what you "really need" is a Mac Pro...
  11. booyah2014 thread starter macrumors member

    Sep 18, 2014
    The only Mac Pro in my budget is the entry level 3.7GHz quad-core i7. Looked at plenty of Benchmarks and the i7 iMac 4.0GHz scored slightly better. Plenty of YouTube comparisons also show the top end 2014/2015 iMac is slightly quicker than the 3.7GHz i7 Pro in most tasks.

    According to a few YouTube comparisons even the 6-core Pro only beats the render times of the top end i7 4.0Ghz iMac by about 10-15 seconds.
  12. Samuelsan2001 macrumors 604

    Oct 24, 2013
    All the 2015 27 inch iMacs are skylake, the 21.5 inch are broadwell. As you say the 2014 i7 will beat the i5 2015 but the GPU differences are minimal.

    The improvements on thermal issues are pretty noticable by all accounts so if reduced noise and heat and increased performance are what you want the 2015 is the way to go.

    Only the OP can decide what his tradeoffs are but spreading false information about specs won't help anyone.
  13. monokakata, Jan 11, 2016
    Last edited: Jan 11, 2016

    monokakata macrumors 68000


    May 8, 2008
    Hilo, Hawai'i
    Over on a Mac Pro thread (either the "will there be a new Mac Pro" or the "Is the Mac Pro a failure" one), a poster named FlatFive made what I thought was an important point, which went something like this: if you're talking about an overnight render, or an even longer one, then getting it done somewhat faster is good but not essential. If you're talking about responsiveness when you're deep into creative mode and you want your changes/effects to appear in real time or nearly so, then differences on the order of only a few seconds can make a real difference in your work.

    That's my experience, too. I'm on a late 2104 retina iMac, top specs, and every day I wish I had more speed when I'm working in Lightroom. I don't like waiting for the image to reform, even though I'm used to it and know to wait.

    When I'm working in video, which is not every day, or even every week, I don't care at all about whether Compressor or FCP X puts out my file in 5 minutes or 7 minutes or 10 minutes. I'm done working on it by then. When I'm editing, the iMac is as responsive as I need in FCP X. When my son, an Avid professional, was visiting and used the iMac to cut a 4 minute piece in MC8, he didn't feel as though the iMac was holding him back when he was editing. Like me, he didn't care how long it took to render and write out.

    So I'd suggest thinking about what part of your creative work is going to go better with speed/responsiveness, and what parts aren't. That might help you decide.
  14. Malus120 macrumors 6502

    Jun 28, 2002
    First, thanks for calling me on my mistake. I had confused the 2015 21” RiMac which features broadwell CPUs, with the 27”, which as you pointed out all feature Skylake CPU’s. While I appreciate the correction and apologize for making a mistake, I don’t appreciate the accusation that I’m somehow trying to spread disinformation to mislead the OP. Just FYI there are better ways to correct someone that don’t imply that they are being purposefully deceitful.

    Getting back to the topic at hand, IMO the OP is clearly concerned about value.

    The post immediately above this one makes a great point regarding the subjectivity of value, probably the best advice in this thread. If you have a responsiveness issue while actually working, even a few seconds can add up to a huge difference over the course of a day/week/month/year, but if the machine is just working while you do something else, as long as its not bottlenecking you from getting other work done it’s probably not worth laying out a bunch of extra cash.

    As I stated in my initial comment, if maximum performance WILL translate into significant additional revenue, then the OP should buy the best they can afford. As has been stated above the maxed 2015 RiMac’s DO offer better performance and better thermals which translate into less throttling during heavy usage and possibly a longer lifespan. Thus if performance=money, then a maxed out 2015 model MAY makes the most sense (although the OP would still want to compare benchmarks for both machines and decide whether the additional performance is worth the cost over a 2014 model)

    That said, given that the OP is concerned about ROI, I would argue that given the similarity in price between the mid spec 2015 model, and the max spec 2014 model, the later of which will perform significantly better, they should definitely CONSIDER the max spec refurbished 2014 RiMac as a way to maximize the machines value to the business while limiting expenses.

    Either way OP you can’t go wrong no matter whichever iMac you choose, just be aware that significant updates are likely later in 2016 on the GPU (FinFIT) and IO (Thunderbolt/USB C 3.1) sides so if you can wait that may be the best choice of all (again, as this is a business expense its all about the opportunity cost of waiting and the ROI on a new machine).
  15. booyah2014 thread starter macrumors member

    Sep 18, 2014
    Malus120 - great reply, thankyou for taking the time. It definitely seems a question of productivity versus running costs. I work alone, I only work on one project at a time, and if I need to leave something to render overnight (as long as it's done by the morning!) it's not a problem. Typically anything I render will be 60-120 minutes and 1080P as a maximum.

    How about....

    If I decided to work with 2.5K CinemaDNG raw instead of 4K within FCPX, would this make a difference?

    I mean, considering what I need, would the following spec meet my needs:

    Late-2015 iMac 5K i5 Q-Core, 3.3GHz
    32GB RAM
    Radeon R9 M395 2GB

    It appeals with the 5K display for the screen real estate, and also being brand new, but not sure if the i5 and the single M395 2GB will be adequate?

    Like I said this is with the view of working with 2.5K CinemaDNG raw instead of 4K footage. I'm also curious how DaVinci Resolve 12 would run!

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