6 Replies Latest reply on Jan 28, 2019 12:22 AM by Mo Moolla

    $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC

    dhuting

      Hey guys, just wanted to report a very interesting yet also frustrating finding.


      I just recently purchased an 18-Core iMac Pro with the 2.3GHz Intel Xeon W and 128GB 2666 MHZ RAM and the Radeon Pro Vega 64 Graphics card, expecting it to be a beast with video editing on Premiere Pro.  Its benchmark score was more than 50,000 with GeekBench...so upon turning on the computer I only installed Premiere Pro CC and began a typical edit, which involved some H.264 100-bit files from the Mavic 2 Pro.

       

      What I have experienced is that when compared to the $5,000 Base-model iMac Pro 6-core I have, is that the performance is not any faster, but in fact is SLOWER in rendering!! How does this make sense?

       

      For example, I am currently looking at 30 hours to render less than 1 hour of H.264 footage which was color corrected and stabilized with Warp Stabilizer.

       

      My question is, how is this even possible? Clearly Adobe has not prepped their software to take advantage of the extra cores OR the extra Ram.

       

       

       

      Please advise.

       

      Returning the computer to Apple thankfully as its within the 14 day return period.  Considering ditching Premiere Pro due to all of the hassles with it locking up and freezing on iMac Pros, but that is a different thread and story altogether.

       

       

       

       

       

      Screenshot of Media Encoder showing 20+ hours remaining + 11 hours elapsed all just to render one 54 minute reel of H.264 footage with warp stabilizer applied:Screen Shot 2019-01-25 at 10.28.59 AM.png

       

       


      GEEKBENCH screenshot:

       

       

      Screen Shot 2019-01-21 at 6.50.45 PM.png

        • 1. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
          Meg The Dog Adobe Community Professional

          This may be of no help at all, but I'd be curious - if you are willing - can you try an export with the Renderer in Media Encoder set to Software Only?

           

          MtD

          • 2. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
            R Neil Haugen Adobe Community Professional & MVP

            You bought a $12,000 computer with 18 creepy-crawling cores? Did I read that right ... 2.3Ghz?

             

            Processing most media especially H.264 in Pr takes a moderately decent number of FAST cores, between 8 and 10. Each with as close as possible to 10GB of RAM per core as possible.

             

            By fast we're talking 3.8Ghz or better. Many of those cores are probably sitting near idle, and the ones in use aren't working fast enough to max you RAM use either.

             

             

            That's a dog. Ship it back!

             

             

            Neil

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            • 3. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
              dhuting Level 1

              Thanks for the recommendation; I have switched it live in Media Encoder but so far no change:

              Screen Shot 2019-01-25 at 10.59.02 AM.png
              Tried the same with switching it to OpenCL from Metal. Its just slowwwwwwwwly creeping

              • 4. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
                dhuting Level 1

                Thanks for the response.   More like a sick dog - even watching videos on the timeline was jittery (like always) - seriously its mind blowing how the performance is so dull given the specs and price point. 

                 

                Re: processor
                The funny thing this is a $2,400 upgrade - their literal best and most expensive upgrade for the iMac Pro processor:


                Here's a screen grab from the Apple Store configure page showing the +$2,400 upgrade for 18-core - no bigger GHz processor available. What a sham.

                Screen Shot 2019-01-25 at 11.02.10 AM.png

                • 5. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
                  R Neil Haugen Adobe Community Professional & MVP

                  Their fastest base CPU is only 3.2Ghz? Huh. That's ... sad.

                   

                  Especially as we've had comments from Mac folks here that the cabinets are not necessarily setup for massive cooling airflows, so over-clocking is rather risky. I don't really know them well, but ... from first glance, the 14 core IF it could be safely OC'd to say 3.8Ghz would be what I'd look into ... but I know near diddly of Mac details.

                   

                  Neil

                  • 6. Re: $12,000 18-Core iMac Pro SLOWER than Base Model w/ Premiere CC
                    Mo Moolla Adobe Community Professional

                    The Mac you have is a decently specced machine BUT what you didn't take into account is that the number of cores is less important than the processor speed.

                    So many end users make this mistake its crazy.

                    Your iMac is set up to get the best out of software that supports multithread processing i.e.. parallel processing.

                    Premiere, AE etc do not run instructions in parallel. They move along a que system much like a conveyor belt. So instructions go to the RAM and then to the CPU "ONE AFTER THE OTHER".

                    So even if you had 50 cores it won't matter.

                    A faster single core processor will outperform a multicore Mac any day in Premiere and AE.

                     

                    Unfortunately you will need to wait until Adobe decides to optimize their software for multithread ability but I don't know when or if this will ever happen.

                    So for now I am afraid the only way to get more speed is to...well theres real not much more you can do besides roll back to High Sierra if you are in that horrible Mojave OS.

                     

                    Mo

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