Help deciding between i9 and vega48

Discussion in 'iMac' started by mortenjensen, Aug 7, 2019.

  1. mortenjensen macrumors regular

    Joined:
    Mar 19, 2012
    #1
    Hi all,
    I am strongly considering buying the upgraded iMac with the 9th gen. CPU. It is for office use, no gaming, some photo editing (RAW-photos). Right now, I am working on 2013 i7 MBA - which is slow, but mostly OK.

    My main concerns are:
    - noise levels: I would want the most quiet setup possible.
    - screen lag: I tested out a MBP 2013 with integrated graphics and the LG 5K. It simply did not work out, lots of lagging.

    My questions:
    - is the i5/580x "enough" for my purposes the foreseeable future? Are there any lagging whatsoever due to the GPU and a slower CPU?
    - if you were to upgrade either the CPU or the GPU, which would you choose?
    - Which setup produces the most noiseless setup: i5/Vega vs. i9/580x?

    I have heard that the Vega48 produces less heat and therefore a quieter mac. Is that so?

    On the other hand, is the i9 "insanely" faster than the i5? And therefore much more future proof?

    Thanks for any thoughts and experiences to share!

    Morten
     
  2. bbnck, Aug 7, 2019
    Last edited: Aug 7, 2019

    bbnck macrumors 6502a

    Joined:
    Mar 19, 2009
    #2
    Well, the 2013 MacBook Pro would lag because it doesn't support 5K displays, so if you were even able to get it to work you might have been running the display at 30 Hz which would result in noticeable cursor lag.

    You need to be more specific about what kind of "screen lag" you have a problem with. Retina displays do require more GPU power than a non-Retina display just from the amount of pixels it has to render alone and this can have an impact on performance in some apps that are not optimised. Even the macOS Window Server was unoptimised and ran poorly on Retina displays until 10.13, so we are talking recent here.

    Is the Radeon Pro 580X enough for your purposes? For photo editing, most likely. It has 8 GB of video memory and over 2,300 cores – it is not a low-end GPU. However, the Radeon Pro Vega 48 (which has over 3,000 cores) is between 30% and 40% faster in some benchmark tests but these are anecdotal based on user reports and might not reflect actual numbers in real-world use (they could be higher or lower).

    What you need to remind yourself – and this goes for other people too – is that just because the Radeon Pro Vega 48 is faster than the Radeon Pro 580X does not mean you need it. Users find it easy to convince themselves because of fear – relying on feelings instead of facts to reach a decision. If the information you come across points towards the Radeon Pro 580X being powerful enough to suit your needs, then buying an iMac with the faster Vega GPU is more than likely unnecessary.

    Hopefully someone here can provide you with some input about how the Radeon Pro 580X performs for photo editing with RAW files.

    Unigine Heaven Benchmarks:

    For Radeon Pro 580X, see: https://forums.macrumors.com/attachments/screenshot-2019-04-04-13-57-09-png.830278

    For Radeon Pro Vega 48, see: https://forums.macrumors.com/attachments/screen-shot-2019-04-04-at-11-05-00-am-png.830341

    Both benchmarks are from this thread.
     
  3. ruslan120 macrumors 6502

    ruslan120

    Joined:
    Jul 12, 2009
    #3
    Rule of thumb is CPU + RAM for photo work, CPU + GPU (+ RAM but not as much needed) for video editing.

    MaxTech has an “avoid these mistakes when buying an iMac video”, I recommend checking it out.
     
  4. nihil0 macrumors regular

    nihil0

    Joined:
    May 19, 2016
    #4
    If you will edit RAW photos in Lr and Ps, you are fine with i5-9600K and R580X. Six cores is max number of cores Lr can utilize. I have i5-7600K and R580 and I can work with both apps without any hiccup. The only way where you would benefit from more CPU power would be HDR and panorama stitching (if you do that a lot). Also, from applying many filters from Filter Gallery in Ps (Blur, Lens Blur and so on).
     
  5. mortenjensen thread starter macrumors regular

    Joined:
    Mar 19, 2012
    #5
    Thanks for the replies:
    - what about the noise issue? Is this a no-issue with the 9th gen? Any difference on this account between Vega and 580x?
    - the 13'' MBP was a 2018 maxed out version. It was terrible (like seconds at times for just minor things, switching programs etc.). My conclusion was that the 13'' MBP + 5K simply was a no-go (don't know if the latest refreshment has changed the situation).

    Well, if i5/580x would be power enough + noiseless enough, it is a bit of a steal compared to a 15'' MBP + 5K LG. Actually, freeing enough Ks to buy a secondary laptop for travel purposes, when the keyboard-gate eventually gets solved.

    Morten
     
  6. nihil0 macrumors regular

    nihil0

    Joined:
    May 19, 2016
    #6
    Regarding the noise, my fans only kick in when I export hundreds of RAW to JPEG photos from Lr at once (I am a wedding photographer). During edits in both apps (and in Luminar 3), the fans are near silent (you can hear them in silent room but it is more like background noise). What I read here on the forums, the 2019 models are more silent than 2017 ones (which I have) no matter what CPU you use.
     
  7. Shivetya macrumors 68000

    Joined:
    Jan 16, 2008
    #7
    the i9 causes the fan to kick on, to 2700rpm for me, far more often than the Vega ever gets the fan up. just playing world of warcraft can cause the fans to kick on and heaven forbid I have a twitch stream open at the same time or a Steam update coming down.

    this is the loudest iMac I have ever owned. EVER. i9/V48. The issue isn't sustained usage only but spikes with an i9 can ramp up a quick touch of heat on that kicks the fan in
     
  8. JacobHarvey, Aug 7, 2019
    Last edited: Aug 7, 2019

    JacobHarvey macrumors newbie

    Joined:
    Apr 2, 2019
    Location:
    Somewhere
    #8
    Keep in mind that the 580X was tested in macOS (using OpenGL - and a pretty ancient version of it as well) while the Vega 48 was tested in Windows 10 (Using DirectX) making the performance difference appear larger than if both were tested in windows. Nevertheless the Vega 48 is, of course, significantly faster than the 580X
     
  9. mmomega macrumors 68040

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #9
    If I click Enhance Details on any photo in LightRoom, all 18 core on my iMac Pro get used and I'll get over 1,200-1,500% cpu usage for a few seconds.
     
  10. nihil0 macrumors regular

    nihil0

    Joined:
    May 19, 2016
    #10
    Probably I have expressed myself wrongly. It doesn't matter how many cores you have, because after utilizing more than 6 cores the performance does not rise equally (excluding HDR and Panorama Stitching, those 2 tasks benefit from more cores). It means that the task will take same time to do with 6 cores what it does with 18. It says so even on Lr website in Optimization tips or whatever it is called and Puget Systems tested that as well.
     
  11. mmomega macrumors 68040

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #11
    I'm sure it does. I was just posting to the thread with my own observance is all.
    I'll try to get a stopwatch from just editing a photo with the exact same filter on the 18 core and the 8 core i9.

    I know "seat of the pants" feel, editing my photos on the i9 seems slower than the 18core but I'll try to grab a time on both just for curiosity sake.
     
  12. mikehalloran macrumors 68000

    Joined:
    Oct 14, 2018
    Location:
    The Sillie Con Valley
    #12
    Old info. Just because it's still on the internet doesn't make it still true.
    Depends on how much of that you do. If a work computer and Time=Money, get an iMac Pro. Especially if fan noise is going to be an issue for you.
     
  13. nihil0 macrumors regular

    nihil0

    Joined:
    May 19, 2016
    #13
    Do you have any recent real world tests to support that? I am genuinely curious because it is hard to find anything other than Puget Systems tests online. Or better yet - no one has ever proved otherwise what is stated on their and Adobe website.
    --- Post Merged, Aug 7, 2019 ---
    If you have means, please do that. I am really curious :).
     
  14. mmomega macrumors 68040

    mmomega

    Joined:
    Dec 30, 2009
    Location:
    DFW, TX
    #14
    Will do.
    At the office on 18coreVega64 at the moment. Applying the filter is almost immediate. Now when I click enhance details, now I have a somewhat measurable time but I'll hold off posting until I can check the i9 at home later. It may be all in my head.

    But I am on Sony A7R3 uncompressed Raw files so around 80-85MB a piece depending on the file, I should be able to post back in a few hours hopefully.
    And hopefully it is so close that I don't want to test anything further :cool:
     
  15. nihil0 macrumors regular

    nihil0

    Joined:
    May 19, 2016
    #15
    Well, I have my i5-7600K R580 and when I apply filter in Lr it does it also almost immediately so that is not good benchmark I guess :). I used it right now on 36 MPx file from Nikon D810. Enhance details on same photo takes around 5 seconds to load and around 10 seconds to apply (measured without stopwatch just good ole counting in head).
     
  16. CWallace macrumors 603

    CWallace

    Joined:
    Aug 17, 2007
    Location:
    Seattle, WA
    #16
    I have a 2017 iMac 5K with an i7 and the 580 and the screen never lags for me. The i7-7700K in my 2017 iMac is generally quiet under light loads, but when I do peg it the fans will ramp up to their 2700RPM maximum, which is audible. GPU loading seems to not affect the fan speed as much.

    As for noise, the i9 has a rated TDP of 95W, but benchmarks have show it can climb to 140W under full load (not sure it can hit those temps in an iMac before thermal throttling kicks in) and people have reported that when lightly-loaded it is surprisingly quiet.

    The R580 has a TDP of 150w (again, it might not be able to hit that in the iMac) and I would expect the Vega 48's TDP to be higher based on the 56/64 figures. But again, when lightly loaded, TDP will be lower.
     
  17. CWallace macrumors 603

    CWallace

    Joined:
    Aug 17, 2007
    Location:
    Seattle, WA
    #17
  18. Ledgem macrumors 68000

    Ledgem

    Joined:
    Jan 18, 2008
    Location:
    Hawaii, USA
    #18
    I don't think you need to worry about screen lag. I'm using a 2015 27" retina iMac with the Radeon R9 M395X (most upgraded card at the time), and it handles the internal display plus a 27" 5K Ultrafine - which isn't even officially supported, according to Apple - both at full resolution, zero lag, zero hit to photo editing performance. The 580x and Vega are better and much better than what I have, respectively, so you should be fine with either.

    The largest photos that I sort and edit are 50 megapixels. I have to say, I'm sort of shocked at the reports of how long Lightroom takes with some of its edits... I use Capture One, and while I occasionally have to wait a second or two for a preview to be generated, adjustments and the like occur instantly or close to it. Capture One does utilize the GPU but from what I can tell, it looks like it hits the processor harder. Adobe is criticized for not optimizing its software well for macOS and I guess that might be the cause. (For what it's worth, I also have 32 GB of RAM and rarely max it out in usage; maybe the Lightroom edits taking seconds are on machines where the RAM is full and a swap file is being utilized.)

    Given my experience with my current computer, I'd say the 15 and 580X is "enough" for you, with some room to grow.

    If you have to choose one to upgrade, upgrade the CPU. You won't be able to adjust the CPU later on, but you'll always have the option of getting an external GPU. There's a slight performance hit when you run a graphics card over Thunderbolt (people argue over the numbers; I usually see people claiming somewhere around 10-15%), but even with the performance hit a vastly more powerful graphics card will still outperform a lesser onboard chip, and graphics card development continues at a pretty fast rate. Vega is the current best chip architecture from AMD, but they're on the verge of releasing a new architecture called Navi that they're claiming is even better (of course). Save your money now, and in two or three years consider getting an eGPU with a slightly older card for cheaper that will still outperform either the Vega or 580x, if you find that the graphics card is really a constraint.

    Can't answer the question about the heat and sound. As to future-proofing, your new iMac will already be "behind" - it doesn't have Apple's T2 chip (which is mostly known for security features, but which apparently does help with speeding up some video encoding functions and boosting SSD speeds), and while it has Thunderbolt 3 and USB 3, it's expected that in a year or two we'll have USB 4 (which is largely just merging USB and Thunderbolt 3). Get what will serve your needs now, knowing that you can upgrade some things later. Trying to stay ahead of the technology curve is a losing battle... the system you're describing should serve you well for 4-5 years, and likely beyond. Actually, what am I saying - you're using a 2013 MacBook Air in 2019, and it's "mostly OK," any configuration of this iMac is going to be amazing for you for many, many years to come.
     
  19. alisalem macrumors member

    Joined:
    Apr 12, 2013
    Location:
    Mississauga, ON
    #19
    The fact that you survived on a 2013 MBA for 6 years means you probably don't care about or need to have the bleeding edge tech to save you time and money. You will more than likely use your new computer with a similar pace to how you were using your MBA. The goal is to obviously have a smoother faster experience. Any 5K iMac with an i5 + SSD should serve that purpose.

    imo i5+580X+SSD = future proofing for your needs... anything beyond that is overkill.
     
  20. JacobHarvey, Aug 8, 2019
    Last edited: Aug 8, 2019

    JacobHarvey macrumors newbie

    Joined:
    Apr 2, 2019
    Location:
    Somewhere
    #20
    iMac CPUs have been socketed for quite a few years now and are upgradeable. Many people have upgraded i5 iMacs to i7 CPUs by themselves (but it is a time consuming and delicate process that requires quite a bit of disassembly). The 2019 iMac continues to use socketed CPUs so a i5 to i9 DIY upgrade would most likely work.

    Nevertheless, I agree that an eGPU presents an easy, useful future upgrade option regardless of which GPU is chosen (in the future both the 580X and Vega 48 will be likely considered quite garbage in a similar timeframe in terms of gaming and other demanding applications). However both GPU options would be completely fine for everyday tasks for many years to come.
     
  21. Vjosullivan macrumors 6502a

    Vjosullivan

    Joined:
    Oct 21, 2013
    #21
    Specs are vague but don't sound taxing.
    i5 is probably enough but i9 is better. If you go for the i5, nagging doubts will mean that you'll always wish you had gone for the i9.
    Get SSD not HDD. This will give to the single greatest improvement in performance.
    Improve CPU rather than GPU. It doesn't sound like you need any enhanced graphics hardware.
    Get 8GB of RAM. It may be enough. If it turns out not, buy more and fit it yourself (open the hatch, slot it in, close the hatch). Takes about 5 minutes and is a third of the price of getting it preinstalled..
     

Share This Page

20 August 7, 2019