11 Replies Latest reply on Feb 4, 2012 5:09 AM by Harm Millaard

    slow rendering


      Hi there,


      I´m using an iMac i7 with 16 GB RAM and a 2 GB grafic card with Premiere Pro CS5.5.10 GB RAM of those 16 are provided for PP and it is configurated for better performance. My problem: While rendering a sequenze of 40 Minutes only 30 % max of the cpu are used (more then 11 GB of RAM are not used during rendering). The renderingtime is something about 10 hours. How can I improve the cpu usage and shorten the rendering time? Any Ideas? Thanks!

        • 1. Re: slow rendering
          Harm Millaard Level 7

          Not much, since the iMAC can not be modified easily. What you would need is a much better disk setup (not possible), a better video card (not possible), a better CPU (maybe possible) and a more balanced system. Unfortunately, the iMAC is not suitable for serious editing, so either live with it, or get a PC.

          • 2. Re: slow rendering
            nefl777 Level 1

            hi there, what kind of sequences are you working on? 

            I've got an iMac with single CPU:

            2.66 GHz intel core i5, 8gb memory. OS: 10.6.8    my graphics card is very ordinary, with 1 one-TB disk that's 7200 Rpm.


            I work with HDV footage. I always figure twice the length of a video is the time to render. So, for a 1 hr video it would be at least 2 hrs. I did one project with ADVHC and it was more than twice for sure... don't remember exactly how long it took.


            I suggest that you try to get a Mac expert to help figure this out because it would seem Mac centered.


            I've often read that when you have software (like Adobe) that has been developed over the years on single CPU architectures, no matter what platform, that when multiple CPUs are introduced, the software spends more time figuring out the threading or timeslicing algorithms than actually doing it's work; and, the threading algorithms are priority over application priority. I know Adobe came out with multithreading for the multi-core processors around version 4 or something but of course I'm no expert.


            This isn't confined to Adobe. It's happened for years on all kinds of platforms with all kinds of software including the operating systems, from Windows to Unix to Mac.


            I know that when I go to my next computer, and it will be a Mac, that I'll probably choose max 2 CPUs at the very most and really load up the memory.


            and one last point, I found that if my disk is even 3/4 full the performance goes south. try clearing up your disk first if you can.

            good luck!

            • 3. Re: slow rendering
              demoncamber Level 1

              Actually, Your mac isn't the issue. i7 with 16gb of ram and your GPU should be perfectly fine for rendering *anything* in CS5.


              I actually have the same issue and I'm on the PC, while rendering it's not maxing out my 6 cores nor my GPU, not sure why it does this, but for some reason it's not rendering like it should be.

              The bottleneck is definitely not our drives.


              While I would say you should have gotten a PC, only because the ability to customize and upgrade is far greater, you have a very powerful mac. And rest assured it's happening to PC users as well And I have 6 cores (1090t), 8gb DDR2 1066 with a GTX470 GPU. Cores are overclocked to 4GHz as well.


              I have plenty of power as you do, but CS5 is just not utilizing it's max potential.


              @nefl777, sorry bud but you are very misinformed and behind the times in terms of technology and what you speak of with the "CPU architectures" etc... You DO want more cores, the more the faster, especially rendering video is, period. None of what you say about the threading algorithms taking higher priorty is true at all. You should do a lot more research.


              And in the world of rendering rigs, you are far better going with PC's. Not Macs. You pay too much $ for macs and you get a locked system with hardly any ability to upgrade. Period.

              • 4. Re: slow rendering
                Harm Millaard Level 7

                Actually, the issue is the iMAC. The ATI video card for one, the single disk for another. The iMAC does not meet minimum requirements even for DV, since it does not have TWO dedicated physical 7200 SATA disks or faster. Let alone for more demanding codecs like AVCHD. The iMAC 27" from May 2011 is only € 3300 here. You can have a € 1800 system that leaves the iMAC in the dust. About overpriced and underperforming systems... However,, since MAC owners seem to have very deep pockets, you can remedy some of the limitations by getting a good Thunderbolt raid system ($$$).


                Your case is similar, since your main bottleneck is your CPU, memory and chipset. All cause it to be dead slow and you did not mention your disk setup, which may also be lacking. Your video card is OK, but held back by the CPU, memory and chipset and possibly your disks.


                I have plenty of power as you do, but CS5 is just not utilizing it's max potential.


                If you call a system that is at least 4 (maybe even 15+) times slower than an Intel based one powerful, then something is wrong here. Well, it the difference between a one hour render or a four hour render for the same timeline.

                • 5. Re: slow rendering
                  demoncamber Level 1

                  Harm, My AMD 1090t, 6 core CPU at 4GHz each core, is hardly a slouch, I still get by more then fine with 1066 8gb DDR2 (DDR3 is not that much faster)

                  Also the nVidia GTX470 (also overclocked) is MORE than powerful enough for cuda rendering.


                  Also, I'm using 2 SATA WD 2TB Black drives for my scratch disks, not in raid.


                  I'm not sure what benchmarks you have been reading, but it's not 4 times slower than an intel based system, intel puts out MANY different CPU's, so you cannot make such a vague statement.


                  Here's some benchmarks to prove you wrong:


                  • 6. Re: slow rendering
                    Harm Millaard Level 7

                    Those benchmarks are absolutely useless. Just consider their source material, the tests they run and their extremely convoluted platforms, that never meet the basic needs of an editor.


                    If you want to see real life tests, go to the PPBM5 Benchmark and run the test yourself.

                    • 7. Re: slow rendering
                      demoncamber Level 1

                      Go look at the test systems they use, those benchmarks are not useless, you are just being ignorant.


                      Here you go, you can really see that 20x performance gain intel has over my cpu



                      ^this is real rendering, not those fake benchmarks... Actual video.

                      • 8. Re: slow rendering
                        demoncamber Level 1

                        oh wow: "HandBrake, freely available, turns the tables even more in favor of AMD’s Thuban design. The Phenom II X6 1090T shaves more than two minutes off of the X4’s transcode, and AMD even manages to beat Core i7-975 by three seconds. Thuban can’t touch Gulftown, but again, we’re talking about the difference between a $295 and $1,000 processor here."

                        • 9. Re: slow rendering
                          Harm Millaard Level 7

                          Go look at the test systems they use, those benchmarks are not useless, you are just being ignorant.


                          There is no denying that fact. I claim this one, even though there are (rare) incidents that not everybody agrees to my ignorance.


                          The hardware under test at Tom's does not meet the practical minimum requirements for CS5.5. See Adobe Forums: System requirements for CS5


                          Almost every test performed has no relevance with regards to editing with CS5.5 and in the occasional test with CS5.x their testing method and the source material used in the test is severly lacking in realism and has no relevance for real life situations. Additionally it can not be replicated.


                          The best 1090t comes out at rank #344 with a GTX card, bested only by 342 Intel systems, among them simple quad cores without overclock, like the i7-860 or i7-920. The worst AMD 1090t system comes in at rank  # 654 out of 659 and is only 32 times slower than a good desktop with an Intel CPU. But I guess that you are afraid of running a real benchmark and finding that your system is just dead slow.


                          Thuban can’t touch Gulftown, but again, we’re talking about the difference between a $295 and $1,000 processor here."


                          That clearly shows how outdated your information is, the i7-980, which is a 6 core and way faster than the i7-975 sells for only € 520, so you are quoting outdated material that is no longer relevant.


                          "Good judgement comes from experience. And experience, well that comes from bad judgement" and

                          "Experience is that marvelous thing that enables you to recognize a mistake, when you make it again".

                          • 10. Re: slow rendering
                            RobinMR Level 1

                            Thanks everybody for putting in some brain. But as you can imagine - I still could not find any solution. By the way, I´m using a thunderbolt 8 TB Raid System.


                            The question is not if the iMac is the best equiped and cheapest computer you can get for editing. I try to figure out why the iMac doesn´t use the whole potential. In fact, it never uses more than a quarter of RAM and CPU capicity.


                            Mostley I work on HD or HDV material recorded by Sony or Panasonic cameras. Sometimes it is recorded in 1080p50, sometimes in 720p50. In my opinion, nothing special.


                            Still need help :-)



                            • 11. Re: slow rendering
                              Harm Millaard Level 7

                              By the way, I´m using a thunderbolt 8 TB Raid System.


                              That is your only solution to make the system behave somewhat faster. However, aside from the $$$ cost of such a Thunderbolt solution, it has the limitation of only 4 PCIe lanes, thus making any raid solution about twice slower than a dedicated PCIe-8x card.