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DaVinci Resolve 16 Slow Rendering

PostPosted: Tue Nov 03, 2020 9:08 am
by Terryble
Hi, I started working with the free version of DaVinci Resolve 16 recently and my rendering times are ridiculously high, the first time I rendered a video, it was in 1920x1080 60f, this took 3.5 hours, it was a 38 minute long video, today I have rendered another video, but this time it was an 8 minute long video (same resolution, same fps) and it took 55 minutes, according to davinci the videos are rendering at a speed of 10 frames per second, which is extremely slow. Generally, at the beginning of the rendering the speed shoots up to about 30 frames per second but after 5 seconds it drops to 10 and it stays there.

Some data
Video files I work with: Mp4- H.264 Codec - 1920x1040 resolution – 60f
Project settings -> Timeline frame rate: 60 - Optimized Media Format: DNxHR HQX (I’m not using Optimized Media files) - Render Cache Format: DNxHR HQX
Render Config. -> Format: QuickTime - Codec: H.264 - Resolution: 1920x1080 HD - Frame Rate: 60 - Quality: Restrict to 30000 Kb/s
*Basically Vimeo 1080P Preset, just changed the quality from 10000 to 30000 Kb/s
Pc: Ryzen 9 3900X (12 Core) - Nvidia RTX 2080 8Gb - 32Gb of memory
I know nothing about video editing, rendering or DaVinci, please help.

Re: DaVinci Resolve 16 Slow Rendering

PostPosted: Tue Nov 03, 2020 12:41 pm
by Peter Chamberlain
H264 in and out will be slow on the free version as it can’t use the GPU hardware decoder/encoder.
But check your GPU driver anyway

Re: DaVinci Resolve 16 Slow Rendering

PostPosted: Tue Nov 03, 2020 2:59 pm
by Gary Hango
Make sure in Preferences the GPU is set to CUDA. If CUDA is not listed, update your graphics driver.

Re: DaVinci Resolve 16 Slow Rendering

PostPosted: Tue Nov 03, 2020 11:50 pm
by Terryble
Peter Chamberlain wrote:H264 in and out will be slow on the free version as it can’t use the GPU hardware decoder/encoder.
But check your GPU driver anyway


Thanks a lot, i'll try that, however, i didn't know that the free version of DaVinvi used the gpu for rendering, I thought only the paid version was able to do that!

Re: DaVinci Resolve 16 Slow Rendering

PostPosted: Wed Nov 04, 2020 4:32 am
by Gary Hango
With the latest version of Resolve, if your driver is not up to date it will not let you select CUDA in the GPU settings and will default to OpenCL. For some reason using OpenCL always seems to result in 10 fps exporting, even without any intensive color correction or FX.

For BMD developers: Why can't OpenCL be better optimized? And if it can't, what use is it having it as a selection? Does anyone actually use it?

Re: DaVinci Resolve 16 Slow Rendering

PostPosted: Wed Nov 04, 2020 4:42 am
by Uli Plank
Actually, Resolve free is using the GPU for rendering even on the PC, but not for encoding – there's a difference.

But if you have any hardware acceleration, either by Intel QuickSync or by NVENC or the AMD counterpart (forgot the name) you can profit a lot from Studio if your source's and/or target's codec is H.264/265.