Looking to buy a 27-inch top end iMac by the end of the year, i5 vs. i7

Discussion in 'iMac' started by Ice Dragon, Jun 8, 2017.

  1. Ice Dragon macrumors 6502a

    Ice Dragon

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    Jun 16, 2009
    #1
    Would it really matter to me whether I choose the i5-7600K or i7-7700K? Where would it make a huge difference? I am probably going to be using it possibly for some gaming and video editing but not anything too extreme.
     
  2. Trebuin macrumors 65816

    Trebuin

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    #2
    Gaming calls for GPUs, but video editing works mostly off CPU. Ask yourself if you can be patient with the video editing or not...if not, get the i7. The i7 is clocked a bit faster & has hyper threading over the i5 that you listed. Geek bench says about 25% multicore, but probably about 10% on single core tasks. Heat will also play a role, though I chose to go faster & disable the hyper threading as it cools down substantially that way.
     
  3. Ice Dragon thread starter macrumors 6502a

    Ice Dragon

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    #3
    Yeah I can probably wait a little. I don't like my computers getting too hot and you already have a decent graphics card in there. I am getting the flash storage and upgrading the RAM myself.
     
  4. BlazednSleepy macrumors 6502a

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    #4

    That isn't a true statement anymore. Most NLE's harness more of the GPU for the majority of editing tasks. CPU still plays an important role, just not like it used to.

    If what you said is indeed nothing too extreme, then the i5 should be fine. I would go for the highest GPU option though, especially for gaming. If you have the money and want to future proof your investment, then go for the i7. I plan on doing that myself.
     
  5. Trebuin macrumors 65816

    Trebuin

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    #5
    That's good to know, could you let me know which software considering Adobe's & a lot of other software I have tried give me a max increase of 10%...with some processes actually slowing down by up to 50% due to lack of polygon work?
     
  6. BlazednSleepy macrumors 6502a

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    #6
    Do you mean what applications take advantage of GPU's? Premiere, FCPX, and Resolve all take advantage of the GPU. I'm not sure if Media Composer does.

    And I'm not sure I quite understand your last statement. You said that Adobe's application slow your CPU down by up to 50%?
     
  7. Trebuin macrumors 65816

    Trebuin

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    #7
    I learned that a lot of what I do complete's faster without any GPU use...but I don't mess with polygons, just simple cleanup. If you add any affects that includes polygons, then yes, the GPU will help there.

    To answer your 50% question: the projects I have run with GPU enabled to improve effects will vary from a 10% decrease in rendering time to around 50% increase. In the end...I stopped messing with the GPU. I've also heard from various places here that OpenGL is at fault (AMD only). I'll talk a look at Resolve & media composer.
     
  8. BlazednSleepy macrumors 6502a

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    #8
    What computer are you currently using?
     
  9. Trebuin macrumors 65816

    Trebuin

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    #9
    2011 MBP, ATI 6770M card with i7 CPU, 512GB SSD, 16GB ram.
     
  10. BlazednSleepy macrumors 6502a

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    #10
    Ya Im not sure how well that computer runs with open cl/ gl.
     
  11. cynics, Jun 8, 2017
    Last edited: Jun 8, 2017

    cynics macrumors G4

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    #11
    True for editing however you'll eventually get to the encode stage which will leverage the CPU heavily. And if you are doing pure software encoding which is still very common (ex Handbrake) you be utilizing the the CPU only.

    Edit: To clarify for video editing I would spend more on upgrading the CPU over the GPU with 2 caveats. 1. GPU has to be dedicated (off CPU). 2. I wasn't doing a Hollywood amount of effects. That's just based on my use and opinion. Because to be perfectly honest I would still start with fast storage for overall better system performance.
     
  12. BlazednSleepy macrumors 6502a

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    #12
    If he's doing, "nothing too extreme", then I doubt he's going to be transcoding tons of footage that will take advantage of the higher-end CPU. I assume you mean transcoding.
     
  13. cynics macrumors G4

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    #13
    Yes, sorry I incorrectly use them interchangeably but you are correct "transcoding". Regardless I've done years of "nothing too extreme" without leveraging my nVidia 775m much however every single project exported will maximize CPU usage.

    I'll concede (through process of playing devils advocate with myself) the only CPU bottleneck you'll encounter with modern Macs is your patience waiting for export. However there can be very real GPU bottlenecks that can effect performance during your edit. That would only be in extreme or incredibly specific task though. I think most people that are "not too extreme" will actually be bottlenecked by their creativity and expertise not hardware but thats an entirely different topic.

    However I would wager to most people even if you did heavily lean on the GPU you'll have a more complex and possibly longer duration project that will utilize the CPU even longer.

    One could take the "if in doubt, max it out" approach and live regret free (finances depending of course). The only reason I would max out the CPU first if I was buying an iMac with video editing in mind is because its the only CPU offered in the iMac with hyper threading which most video editing software will utilize along with programs that accompany that workload.

    IMO there is a method to Apples madness by offering relatively fast CPU options with moderately fast GPU options. Even the upcoming iMac Pro takes a similar approach when comparing Vega vs 18 core Xeon while specially referencing video editing.
     
  14. Ice Dragon thread starter macrumors 6502a

    Ice Dragon

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    Jun 16, 2009
    #14
    I talked to a friend of mine who just said "Why not? Get the i7!" to which I replied "Well that $200, could be spent on getting more RAM." Upgrading to i7 would push it over $3,000 before the RAM upgrade (I'm doing it through MacSales.com) and as nuts as this would be, I kind of want to get 64 GB of RAM just because.
     
  15. BlazednSleepy macrumors 6502a

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    #15
    Between the Ram and CPU upgrade. The CPU upgrade is the safer bet. You can upgrade the ram later down the line when you feel you really need it.
     
  16. stallie macrumors newbie

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    Apr 2, 2010
    #16
    Yes, that was my logic with my SSD option. The i5 /8gb will do me now, but the bit of extra for the i7 might stretch the replacemtn another year or two in the future. The ram upgrade can wait and DIY later.
     
  17. joema2 macrumors 65816

    joema2

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    #17
  18. BlazednSleepy macrumors 6502a

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    #18
    It is correct as a general statement. When editing, the majority of modern NLE's harness more of the GPU (if you actually set up your project correctly). Exporting? Transcoding? Rendering clips? CPU dominant, we established that above. I did watch part of the Video's you posted and he used the native XAVC footage for playback and never converted to a proper codec for editing. No wonder it played like crap in Resolve. The newest version coming may perform better though. And as for you're post....4K H.264? Cmon man. You don't edit such a highly compressed format at such a high resolution. No wonder your CPU was peaking out...PRO RES my friend.

    The CPU is used when playing back native/compressed footage. Once it's properly transcoded for editing, the GPU takes over the majority of the NLE's processes. If the NLE's is optimized for doing that, that is.
     
  19. joema2 macrumors 65816

    joema2

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    #19
    The intro to Premiere video on Adobe's web site right now says this: "...the 64-bit optimized Mercury Playback Engine...allows editors to work at...4K and beyond...without the need for time-consuming transcoding".

    My documentary film crew can shoot a terabyte of 4k H264 per *day*. We can't blithely transcode that to ProRes in the field. Selects and dailies must be done on the camera native content. Yes we eventually create proxies, and our downstream editors use a proxy-only ProRes workflow. For our current documentary project, generating those takes one *week*. That in turn shows the importance of being able to do initial editing on H264 4k camera-native content.

    FCPX has always had built-in seamless transcoding for proxies. Premiere never had that until recently -- their position was Mercury Playback was so fast it wasn't needed. With the widespread use of H264 4k acquisition, this concept broke down, so they added proxy (which works well). Before that for the last seven years, if any Premiere editor needed proxy, he had to manually generate this himself and care for the linking. That was not the common, general procedure. The general procedure was camera native, which was CPU-bound. That worked OK on H264 up until 4k.
     
  20. BlazednSleepy macrumors 6502a

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    #20

    Sure, but it doesn't say anything about it doing it smoothly.

    Okay, but it still doesn't change the fact that editing highly compressed footage is going to tax the CPU. That's how it works.
     
  21. epca12 macrumors regular

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    Jun 11, 2017
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    UK
    #21
    I would focus on the graphics card, the 580 seems like a noticeable jump
     

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