Use of computer resources by NLEs
COW Forums : Creative Community Conversations (was FCPX Debates)
Hello all, Here's my big question. Resolve is running very slow for me. Folks have advised selling my new 2019 iMac 3.6 Hz computer, replacing the Fusion drive, replacing the 575X Radeon Pro GPU (4 G), replacing my Firewire ext drives . . . Is Resolve just too demanding for ordinary computer resources? Does Premiere function with less demand on the computer and its parts? How about other NLEs? No one seems to talk about this. Thank you, Robert
Independent/personal/avant-garde cinema, New York City
Currently experimenting with iMac 2019, Catalina
3.6 MHz 8-Core Intel Core i9
16 GB Memory
GPU Radeon Pro 575X (4 GB)
Well, the iMac seems pretty decent. But my understanding is that the fusion drives run slow--that may be an issue. Even more significant--the Firewire drives/connection speeds. Apple basically moved to thunderbolt 7 years ago. Firewire is likely be too old/too slow for your needs.
Assuming you have your edit media on external drives, your next step might be to get a nice Thunderbolt 3 external drive and see if that helps. I'm sure it will.
And I would hold off getting a new iMac for a couple of months; the rumor is that Apple will be releasing a new one before the end of the year. (But you may not even need it if the Thunderbolt drives helps your performance.). Good luck.
Yes, dump the FireWire drives, I have the same iMac as yours, but with the 8GB card and SSD Thunderbolt drives and i have no speed problems at all
[Robert Withers] "Resolve is running very slow for me. Folks have advised selling my new 2019 iMac 3.6 Hz computer, replacing the Fusion drive, replacing the 575X Radeon Pro GPU (4 G), replacing my Firewire ext drives . . . Is Resolve just too demanding for ordinary computer resources? Does Premiere function with less demand on the computer and its parts? How about other NLEs? No one seems to talk about this. "
From a performance standpoint there is a complex relationship between the codec, operating system, NLE and hardware. Within each of those there are many variations.
E.g, there is no single H.264 codec -- there are many variations which are internally different and place different demands on the NLE & hardware. On Macs alone there are four main hardware accelerators: Intel Quick Sync, Apple's T2, nVidia's NVDEC/NVENC, and AMD's UVD/VCE. *Each* of those exists in various versions. Each NLE harnesses those (or fails to) in various ways.
That is just the decode & encode phase. The render phase is typically GPU oriented, and each effect or plugin has various capability to leverage that. Sometimes a single plugin (e.g, Neat Video) can be re-configured to use a specific mix of CPU cores and GPU.
Within a single NLE on the same OS and hardware, performance of that NLE can vary based on NLE version. In general Resolve has greatly improved performance in *recent* versions. Within a *single* NLE version on a single codec on the same hardware, the NLE can be reconfigured which affects performance (viewer resolution, proxies, media & cache placement, etc). Resolve has various ways to improve performance: https://blog.frame.io/2020/02/24/davinci-resolve-performance/
What does "performance" even mean? Render time? Export time (which is easy to measure)? Or is it viewer update rate or lag time to JKL keyboard input (harder to measure)?
People often focus on I/O but if you're using a compressed codec it it unlikely IO-limited. After all the puny CPU in the camera managed to write that. OTOH a FireWire HDD is typically quite slow by today's standards. For HDDs over 5 yrs old, studies have shown a 20% annual failure rate. Just from a reliability standpoint I would replace all those. If using a less compressed codec such as ProRes it is easy to encounter an I/O limit. If the NLE is internally using low-compression render files (e.g, FCPX uses ProRes 422 by default) you can hit a IO limit even on a compressed camera codec.
While video editing IO profiles are often viewed as dominated by large sequential operations, some NLE's (e.g, FCPX) also emit a high-intensity stream of small random IOs. With FCPX this is due to the underlying SQLite database and operations for thumbnails, waveforms and plist files. Ideally you want to segreate those IO streams on separate devices to avoid conflict.
To answer your last question, in general FCPX and current versions of Resolve are quite fast, and Premiere is less so - especially on Mac. But this varies with all of the above-listed items.
With Resolve, everything is about the GPU. You could have the fastest processor in the world, 600 terabytes of RAM, and lightning-fast drives and they won't make a difference if your GPU is not up to spec. Your 4-gigabyte GPU is likely the bottleneck here.
BMD hasn't updated their hardware configuration guide for Resolve 16 (unless they recently did so, I haven't checked), but your GPU is under spec even for Resolve 15.
Following up with a quote from the Resolve 15 configuration guide, with some light editing to fix punctuation errors and typos (I just checked and it has not yet been updated for v. 16):
"The key thing to keep in mind when selecting your config is that unlike traditional editing, grading, audio post or finishing systems, imaging processing in DaVinci Resolve is graphics processor (GPU) based and so some of the features require a higher end GPU than you might be accustomed to. High-performance GPUs or multiple GPUs will offer the best experience."
Also with respect to iMacs: "The 27" Retina 5K iMac with 4GB GPU RAM will reach the GPU capabilities sooner with UHD timelines and when using optical flow speed changes, temporal processing and noise reduction, even at lower resolutions and with fewer editing tracks or color grading nodes. Performance of many of the older model iMacs with 2GB of GPU memory is limited even with HD images."
And one other thought: before you despair and decide you need a new computer, you could at least try some of these settings to improve playback:
When you say Resolve is "slow" it's not clear whether you mean it can't play back at full speed or whether it takes a long time for it to complete tasks you ask it to do, especially on the color page.
Final Cut "seems" faster and maybe it is because it's optimized for the Mac, but a lot of the apparent speed difference is an illusion because by default FCPX render-caches everything for smooth playback. You can set up Resolve to do this as well, and you can render-cache every clip individually or just some clips, or even nodes on the color page.
[Brad Hurley] "Final Cut "seems" faster and maybe it is because it's optimized for the Mac, but a lot of the apparent speed difference is an illusion because by default FCPX render-caches everything for smooth playback. You can set up Resolve to do this as well, and you can render-cache every clip individually or just some clips, or even nodes on the color page."
I also used to say that, but the current situation is more complex. FCPX is "fast" (IOW extremely responsive with low lag) due to meticulous attention to the software code path which implements certain functions. This is especially notable in the fluid, hyper-responsive skimmer and associated viewer. This is regardless of whether FCPX background rendering is on or off.
This was initially attributed to Apple's single-platform focus. It seemed superficially plausible because Premiere and Resolve were clunky and slow (not long ago).
Today the latest versions of Resolve are really fast in most metrics. The interactive performance is very good as measured by lag to executing JKL input, viewer update rate, etc. Encode/decode performance is faster than FCPX in some cases -- yet Resolve is cross platform. Premiere export performance has improved dramatically in some cases but the interactive performance on Mac for certain codecs is still very sluggish. This is especially seen on Sony 4k XAVC-S and -L, and Panasonic 4k 10-bit 4:2:2 All-Intra.
With cross-platform Resolve now encroaching on FCPX interactive and export performance, this apparently diminishes the argument that FCPX achieved this via single-platform focus.
Re the OP issue of "Resolve is slow, maybe my 2019 6-core iMac 27 can't handle it", I tend to doubt that. He only has the 575X GPU which IMO is not optimal (esp. for Resolve) but even the top Vega 48 GPU is 43% faster on GeekBench. That's a very useful improvement but it won't necessarily transform the entire workload.
In general I'd get the top GPU for any new Mac, but it's possible his situation is a bottleneck somewhere else, or Resolve can be configured to better cache render files.
He could also experiment with eGPUs but that is another trial-and-error science project.