iMac Pro Graphical glitches on new iMac Pro - driver issue or worse? Anyone else experiencing this?

Discussion in 'iMac' started by arepty, Apr 9, 2018.

  1. arepty macrumors newbie


    Nov 22, 2007
    Bremen, Germany
    Hi everyone,

    I recently got a new iMac Pro (woohoo) and I noticed some strange graphical glitches while doing a few things, such as playing Diablo III. Here's what it looks like:

    I also had a few issues with the image editor Acorn, so I asked the author about it:

    Turns out the Acorn issues are gone if I use OpenGL instead of Metal as Acorn's renderer. This makes me think it's a driver issue, which sounds plausible given the Radeon Vega 56 GPU is rather new, but I'd like to hear from other iMac Pro users to see whether it's actually just software or whether I should see about getting the computer repaired/replaced.

  2. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    The glitches you are seeing in Diablo III vaguely remind me of the incessant, maddening glitches that I am experiencing with my MULTIPLE iMac Pros.

    First, I got my 8-core iMac Pro the second week in January. I migrated from my 2014 5K iMac and have experienced glitches since day one. They seem to happen after the computer has been booted for at least a couple hours. I've always used my Macs aggressively with at least 20 apps open and around 30gb of ram active. My two previous iMacs handled this fairly flawlessly.

    So I contacted Apple Support online chat, they had me go through the basics of resetting NVRAM, SMC, safe mode, everything you can think of to start off with. Nothing helped. Then I contacted Apple Support phone and they did the same things, then had me reinstall the OS, and then told me that it sounded like a hardware error and to make a Genius Bar appointment. So I did, they couldn't replicate the problem, and concluded that my computer was fine after erasing it and "resetting the iOS portion" of the iMac Pro.

    Suffice it to say, I still experienced the problem. Mind you, this problem is screenshottable. So it should be software related, right? But it looks like GPU artifacts like your Diablo III screenshots. So I gave up for a while and just dealt with it, quitting the apps experiencing the problem and opening them again.

    When I got frustrated enough in March after trying basically everything Apple had told me, I emailed Tim Cook expressing my disappointment at having spent $7,000 and going through the proper support channels and getting nowhere. I was contacted by the executive liaison's office saying they were dedicated to figuring this out for me. I did data captures, tons of screenshots, worked with the engineers and they concluded it was hardware again.

    This time I took it to the Apple Store, waited a week, they replaced the logic board but when putting it back in the computer they screwed up the ethernet port and had to send me a brand new iMac Pro from China which took almost another week. I thought, awesome, I have a brand new iMac Pro, surely this will fix the problem. I migrated from my Time Machine backup and the computer was fine... for 6 hours. The problem came back.

    At this point, I have brand new hardware, it has to be software, right? So I contacted the liaison again and did more data captures and more screenshots and they concluded that I needed to get the logic board replaced... how? How could it be possible that I got two defective iMac Pros in a row? I just couldn't believe it. I told them to seriously reconsider this because I didn't believe any Apple engineer who genuinely knew the whole story would think I needed more new hardware. So they did reconsider and suggested I erase everything and start over from scratch with no migration.

    I painstakingly reinstalled everything with screenshots of my app settings saved in my Dropbox. And... the problem is back. At this point, I am totally lost. My files and my apps worked on my iMac 5K but they don't work on not one but two different iMac Pros. Sorry for hijacking your post but I had to get this off my chest in the hopes that someone will have any clue as to what I should do next. Here's the apps I run regularly:

    Slack (used heavily)
    Fantastical (experiences glitches)
    Mail (experiences minor glitches in to, cc, bcc, subject fields / used heavily)
    Chrome (experiences minor glitches in app chrome / used heavily)
    Notes (experiences heavy glitches in note body panes / used heavily)
    Reeder (experiences minor glitches in article list / used heavily)
    Messages (experiences heavy glitches in conversation panes / used heavily)
    Plex Media Server
    iFlicks 2
    iStat Menus
    Creative Cloud
    Illustrator (never experiences glitches / used heavily)
    Photoshop (never experiences glitches)

    The apps that experience glitches are all cocoa apps using native appkit frameworks and are mostly apple-developed applications. Of note is that Adobe apps do not experience this issue and are some of my most used and intensive applications.

    Additionally, this almost always occurs in a non-active window behind another window. If there are shadows or transparencies, the glitch is more likely to happen and or be located only within the shadow of another app. I tried turning off reduce transparency and high contrast mode and both have no effect on the problem.

    Does anyone have any clue as to what this is? I'm literally at the point of needing to sell this computer and go back to a 5K iMac.

    Screen Shot 2018-01-13 at 00.29.43.png
    Screen Shot 2018-05-16 at 18.27.58.png
  3. richinaus, May 16, 2018
    Last edited: May 16, 2018

    richinaus macrumors 6502a

    Oct 26, 2014
    I had a similar problem with my first iMac pro which had the Vega 56. It was glitching a cross apps similar to your image, but not to the same extent. I also noticed it didn’t do this on Apple apps. I told the guys in store and sent them screen shots too but did nothing about it.
    I returned that one and got the Vega 64 and I have not had the same issues and also use it quite ‘aggressively’.

    I agree though I was very unimpressed how they could release a machine like this, given the lack of Mac Pro updates, and was surprised by the glitches.

    The other odd thing is my current machine boots a lot faster than the glitchy one, and just seems to be a much better overall experience. I do have to wonder if there are bad machines out there, and is not just GPU related.

    Will post an image later when back on my Mac, as now since I had a dig through my photos, it was very similar to yours.

    Also if I was in your position I would insist they change the machine to a new one.
  4. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    That's strange because it almost exclusively glitches on Apple's apps for me, not third party apps. I'm at four months wit this computer so I'm not sure how many options I have to return it and exchange for an even more expensive one. Also, they have given me a brand new machine and it does the same thing.
  5. mmomega macrumors demi-god


    Dec 30, 2009
    DFW, TX
    Sell, Sell, Sell. If something is aggrivating it will just continue to.
    Sell, even taking a loss will be less stress than the constant daily aggrivation of having a machine that doesn't work the way you want it to.
    Hoping it will fix itself won't work. Find something else and enjoy that.
  6. macguru9999 macrumors newbie

    Aug 9, 2006
    Re: the glitches... Pity you cant unplug the ATI card and put in an NVIDIA 1080. Oh wait ... you can but only in an external box. I had a 7950 in my Mac Pro and sent it back. Not too bad but the screen would flash (refresh) every now and then. really annoying. The 5870 did it a couple of times too but not as much. Ended up with an NVIDIA 680GTX. I hope when the new Mac Pro comes out we will be able to choose our GPUs...
  7. joema2 macrumors 68000


    Sep 3, 2013
    Wow, what a story. I'm on my 2nd 10-core iMac Pro; I had an intermittent transient brightness fluctuation on light-colored objects in FCPX. This only happened on the iMP not my 2017 iMac. I contacted Pro Apps support, they thought it was hardware -- it seemed to only happen after the machine warmed up. Apple tried to replace the logic board, broke the machine beyond repair, gave me a replacement from China. The new machine had the same problem.

    In my case I eventually tracked it to a transient intermittent flickering problem caused by FCPX fleetingly mis-identifying the color space of the project. It was all REC 709 but apparently in some kind of race condition it would momentarily switch to REC 601 (NTSC). It was very timing sensitive, unpredictable, and had the appearance of thermal-related flickering. The solution was manually re-flag all clips as REC 709 even though they were already so tagged.

    In Apple's defense this was an extremely difficult, misleading problem that had all the earmarks of hardware. However Pro Apps escalation support should have used a symptom search tool to scan all similar reports and identified it as FCPX.

    I think they were preconditioned to believe it's hardware due to (a) the specific symptoms and (b) people like you are experiencing GPU-related hardware issues.

    Your case clearly looks like hardware. The fact it's been replaced doesn't eliminate that possibility. It could be a bad manufacturing batch. It could be a low-level issue with some compositing layer or how Metal interacts with the Vega GPU.

    I think 10.13.4 had some fixes for AMD graphical corruption on the iMP. Are you on that? The fact there have been *any* fixes for graphical corruption on the iMac Pro implies (a) it's been a problem and (b) it might not be totally fixed yet.

    This is obviously a serious issue. Whether it's hardware or low-level software, Apple needs to pursue this.

    if you had time, you could help by trimming down the replication scenario. E.g, reformat, re-intall just the minimum apps to reproduce this. Try to get it small as possible. Take a Time Machine or Carbon Copy backup to preserve that state. Admittedly this can be very time consuming, especially for this type of problem.

    With that backup in hand, go to the Apple Store and load it on an iMac Pro and see if it can be reproduced. If they don't cooperate, talk directly to the store manager and explain the background and you're working with executive liaison.

    If it can be reproduced by loading the backup (even if it takes two hrs to warm up the machine), call your Apple escalation support contacts and send them a portable drive -- if they are willing. IMO they should be.

    If a portable replication scenario is impossible or it's too time consuming, IMO Apple should either (a) have an engineer remotely connect for debugging or (b) have you ship them the entire machine.

    I don't know Apple's procedure for cases like this, but in a previous job that's what I did. I would remotely debug it live or compile and link "instrumented" versions of the software to gather more info or have the customer send me a hard drive with a portable scenario (if achievable) or as a last resort have them ship the entire machine.
  8. pat500000 Suspended


    Jun 3, 2015
    Luckily my Mac Pro 2010runs fines with d3....this is sad
  9. Luis Ortega macrumors 6502a

    May 10, 2007
    Fetcham Surrey UK
    It sounds like the imp isn't yet ready for prime time.
    I was considering getting the base option when it came out, but now I'm glad that I stayed away from it.
  10. SecuritySteve macrumors 6502a


    Jul 6, 2017
    The issue is definitely a driver issue. We probably won't see updates for these issues until the next stable release of macOS (10.14) at WWDC. It's sad, but it's true.

    I've noticed the same issues on my iMP Vega 64 in Diablo 3, yet in WoW (which is run in Metal) there are few to no issues at all. My advice would be to wait it out, turn off reflections in D3, and deal with the minor graphics problems for the next month or two until we can update to the new OS.
  11. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    I hear what you're saying. I know that ideally I would start from nothing and only use Apple apps and use the computer for X amount of hours to see if I experience the problem. Unfortunately I have work to do and if I don't use any apps but Apple's, I can't even use the computer and will end up using my laptop for work and not stressing this iMac Pro enough to produce the problem. I can't imagine a scenario where I would have this much time, even though I know it to be the only solution. Additionally, getting this problem to reproduce takes usually 2 hours after a restart and it takes me using the computer to its fullest like I normally do. I would have to describe a usage scenario to them that is inscrutable even to me.

    My biggest lead so far is that I *think* this only occurs when Adobe Illustrator is open. It may also be related to other Adobe apps like Photoshop, but I primarily use Illustrator daily. I closed Illustrator last night and will not open it again on this computer for a few days. Typically the problem shows up at least 20 times per day so if I see none of this, then I will know it is Adobe applications being incompatible with the iMac Pro. But my question is this: If, indeed, that is the case, what are my options? Clearly on two machines with identical hardware the same problem occurs with the Adobe software. I can't just get another one, because the chance that it will occur again is almost a certainty. Do I sell this computer and go back to a 5K iMac? Do I do what another user mentioned and get the upgraded Vega 64?

    I have been talking to my liaison with these exact questions and they completely understand where I'm coming from. Their hardline is that it's not their hardware, it's my software. They want to do what they can to help, but ultimately they don't feel this is their problem. And you'd never get Apple to admit that their drivers aren't functioning properly, it has to be that Adobe's software isn't optimized for their bugs.
  12. _Kiki_ macrumors 6502a

    Aug 13, 2017
    can be the problem with drivers under High Sierra, looks quite similar to problem with MacBook Pro 15 2016 (also AMD GPU) under early version of Sierra

    can you test the GPU under Windows 10 ?
  13. joema2 macrumors 68000


    Sep 3, 2013
    That would seem to help define the boundaries. However attributing cause and effect for this type of problem can be misleading. If it's a sliver-thin multi-thread timing window or some kind of cache state issue, Illustrator could "prime" the system for the failure yet be doing nothing wrong. This makes it look like Illustrator's at fault when their app simply is a catalyst for it.

    It might help if you shot some video of it, if only with a cell phone. In the above screen shot it looks like Apple Mail. Is that right? Either the app or some final macOS compositor layer is responsible for that. Illustrator in its own window can't corrupt the non-overlapping window of a different app.

    My gut feel is it's not unique to Vega 56. I wouldn't do anything drastic yet.

    How do they possibly know that? Is this the same liaison that recommend you replace the logic board on your 2nd iMac Pro? If they were so confident it's hardware then, whey are they equally confident it's non-Apple software now? How do they know it's not another graphical corruption problem like the one fixed in 10.13.4 which is listed in the release notes: "Fixes graphics corruption issues affecting certain apps on iMac Pro"

    Even though it's time consuming I recommend seeing if it happens when not running Adobe apps. If possible set up your cell phone or a video camera and shoot some video of it.
  14. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    Thanks for taking the time to respond to me, I really appreciate it. I hadn't considered that Illustrator may not be at fault but rather primes the system to cause the problem. It does seem odd that Illustrator itself has no graphical glitches but when it is running other apps do.

    So far I have not seen the glitch today. I have not opened any Adobe apps (besides the always running Creative Cloud app in the menubar) since yesterday. The screenshot is actually of Messages. A video would show that when I click a background window with the glitches to bring it to the foreground, the glitches disappear. And sometimes if I run a window's shadow over another window, the underlying window will experience glitches that follow the shadows. Sometimes if I see the glitch and I use the screenshot crosshairs, as the crosshairs envelop the glitch, the glitch disappears from underneath making it impossible to screenshot.

    It has been since January, about 5 months now. Does it still seem drastic to think about upgrading and/or replacing with a different model? How long should I troubleshoot this before I am just wasting my time?

    What happened with Apple's liaison and their hardware team, which they won't admit, is that when they suggested I get another new logic board, the engineers hadn't considered that this was a replacement iMac Pro already. I told the liaison that there was no way they would be recommending this if they had known that. She said she would talk to them and when they came back said that upon reconsideration they agreed that it was not likely hardware as I had suggested. I have to assume that they wouldn't give up that easily just because a customer has a hunch; I really think they didn't look at the whole case file. As for how do they know it's not their software? They don't but they can't admit that it is. They are stuck with the fact that whatever the release is the best they have. They can't divulge unreleased software or admit to a corruption bug. They have no choice but to lay the blame on my specific software setup.

    If I see the problem again without Adobe apps open, I will take a video with my phone.
  15. richinaus macrumors 6502a

    Oct 26, 2014
    Keep pushing it - it is definitely an issue, and one I wouldn't accept.
    My app use hasn't changed at all between my old and current iMac pro and I never get these issues now, but did constantly on the first computer. It is Apples problem and is not really acceptable on a machine this expensive.
  16. pixelatedscraps, May 18, 2018
    Last edited: May 18, 2018

    pixelatedscraps macrumors 6502


    Jul 11, 2017
    Hong Kong
    A shame its been so frustrating for you. I've had zero problems with my iMP but run a different set of apps to you, I would say about 50% of these are running at any one time. The iMP is in use between 8-12 hours per day and while not thrashed, is pretty well used:

    Capture One 11
    Lightroom Classic CC
    Photoshop CC
    Illustrator CC
    InDesign CC
    Bridge CC
    DaVinci Resolve 15
    Radio Silence
    Synology Assistant
    Google Drive
    Carbon Copy Cloner

    It seems like you're getting closer to confirming where the issue stems from - and it definitely sounds like its got something to do with a driver incompatibility with one or more of your apps. I would look suspiciously at Adobe (after Apple and AMD driver signatures) as they've most forgotten how to refine their software over the last few years with some very sloppy releases.

    Hope you get it resolved!
  17. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    Well, I have not opened Illustrator at all but I did inadvertently open Adobe Acrobat and kicked myself afterwards because the glitches came back a short while after I closed Acrobat. I took a video this time so you guys can see what I'm talking about.

    iPhone Photo:
    Screenshot: Shot 2018-05-18 at 16.39.03.png?dl=0
    iPhone Video:
  18. joema2 macrumors 68000


    Sep 3, 2013
    Thanks for doing this. Very interesting. In this case they only appeared on Chrome. Or were there some at the bottom I couldn't see? Regardless, it's obviously not only Chrome because previously you posted some from Messenger.

    IMO this is very unlikely a software problem with Adobe apps. One user-mode app cannot affect the address space, screen drawing behavior or input queue of another app. If that happens it's an OS deficiency. This basic principle should be well understood by any escalation support engineer.

    The only exception is if an app loads a kernel (or system) extension then that can affect system-wide behavior, but to my knowledge Adobe apps don't do that. High Sierra disallows this anyway, so even IF it happened you'd know about it. You'd have to go to System Preferences>Security & Privacy>General, and there'd be a warning at the bottom saying 'System software from developer "Adobe" was blocked from loading'.

    If this didn't happen, you are only running user mode apps. One app cannot corrupt the memory or graphical context of another app.

    I suggest you make additional videos, hopefully showing only Apple apps, then contact Apple again and show them those. Let them know that making vague excuses about "it's your other apps" is not technically supported.
  19. richinaus macrumors 6502a

    Oct 26, 2014
    I don’t believe it is app related as why would I have had the same issues with one machine but not the other, using identical apps (inc adobe suite).......
  20. jtrwallace macrumors member


    Jul 4, 2007
    Santa Cruz, CA
    I don't believe it's app related anymore either, but the same exact thing DID happen on two different machines with the same configuration. It looks like this video card is not compatible with macOS High Sierra. I don't see how Apple can fix this besides fixing their OS.

    And, to reply to the original poster, I checked out Diablo III and lo and behold I have the same exact graphical glitch that he has. This is a widespread, consistent, repeatable problem with this specific GPU. Here's a video of the Diablo III glitch on my iMac Pro:
  21. richinaus macrumors 6502a

    Oct 26, 2014
    So my first machine was a vega 56 and current one is Vega 64.
    There were some really minor artefacts but the latest update made it perfect.

    I am wondering if this is a Vega 56 issue with drivers?

    But as I mentioned my whole machine simply feels a lot better in all ways. There was a somewhat overall sluggish feel to my original machine.

    This all makes me believe there are machines out there that have some issues and as such Apple should be replacing.
  22. HumpYourWayUp macrumors regular


    Jun 14, 2007
    My iMac Pro had graphics issues with Blackmagic Fusion 9, red dots appeared randomly.
    But the first macOS Update fixed it! No problems ever since.
    IMHO some apps need updates and MacOS might also need another patch.
    On a side note: Today I tried Pillars of Eternity 2: Deadfire which runs perfectly. Highly recommended!
  23. DTVID macrumors newbie


    May 16, 2018
    Moving on from my last post regarding the new iMac Pro and FCPX, after a few months, I am no further forward. I have a constant link with a guy at Apple on the FCPX side, and he has been excellent, as have the guys at the Business Team at the Southampton Apple Store, unfortunately, we are all in the same situation where no one can at this stage work out why the iMac Pro has issues working with FCPX. I make movies that are around and hour and a half long, using AVCHD and 4k footage from Sony camaras. I have been working the same way for a while now, all on my 27" Retina iMac, which has been fine, and still works well. I did have an issue making movies through compressor on the 27" Retina, but this was solved by expanding the energy saving settings to maximum. I now have two iMac Pro's with exactly the same spec, as well as the original Mac, and yet the to Pro's perform differently even with the same project! I have seen random frames appearing on the timeline, glitching which appears in the final production, if I manage to produce a film on the Pro, and regular frame dropping even when working in Proxy. I'm in a fortunate position that I can compare performance with the exact same project on the older iMac, compared to the Pro, and at this time, I see no advantage with the Pro, in fact, it is taking me longer to produce on the Pro, as I have to detach the external drive and plug into the older iMac to produce the movie through Compressor.
    Apple are apparently working on this, and I have sent them more screenshots and data records than I can remember, but at this stage, all the Pro has done, has cost me time and money, so I hope Apple can get the issues sorted out quickly.
  24. ColdCase macrumors 68030

    Feb 10, 2008
    I have to do the same thing, output the FCPX movie to a public folder, jump on my MacPro and use the older Compressor App there (and older OS). Otherwise I get permission problems when trying to view the video loaded on the server. I thought is was an OS/Compressor issue, but perhaps it is the iMac Pro itself.

    I have a fast LAN, so file sharing is about as quick as using a USB hard drive.
  25. joema2 macrumors 68000


    Sep 3, 2013
    There are several issues here. This thread was mainly about intermittent graphical corruption on iMac Pros running various software, not just FCPX. The one described above is dots or graphical garbage intermittently appearing on the screen.

    However there's a specific graphical corruption problem in FCPX that seems more common on iMac Pros if using AVCHD or maybe Sony XAVC-S. That specific problem is seen as brightness fluctuations or flickering on bright objects. In that case the workaround is manually re-flag all media in FCPX as REC 709 color space, then delete and recreate any current render and proxy files.

    I haven't seen frame dropping on the iMac Pro when using proxies in FCPX, but there are performance problems on the iMac Pro when handling certain types of H264. IOW a 10-core Vega 64 iMac Pro can be slower than a 2017 iMac in certain cases. As of today this is not yet fixed in FCPX 10.4.2 and macOS 10.13.5.

    I just re-ran performance tests on a top-spec iMac 27 and 10-core Vega 64 iMac Pro, and obtained the following numbers:

    Export from 4k Sony XAVC-S, clip length = 10:17

    Output = 4k H264 Fast Encode, 2017 iMac 27 = 5:53, 10-core Vega 64 iMac Pro = 7:10
    Output = 4k H264 Better Quality, 2017 iMac 27 = 11:25, 10-core Vega 64 iMac Pro = 14:49
    Output = 1080p H264 Fast Encode, 2017 iMac 27 = 5:53, 10-core Vega 64 iMac Pro = 4:00

    So at least the iMac Pro is faster at encoding to a 1080p H264 file, but it's slower than a 2017 iMac at encoding to a 4k H264 file.

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