H.265 10bit 5k no GPU acceleration, but works in VLC & PPro

CPU Intel i7-7700HQ
RAM 32.0 GB
GPU Intel HD Graphics 630
GPU NVIDIA GeForce GTX 1060 (mobile)
DaVinci Resolve Studio

I have footage from Panasonic GH5:
H.265 10bit 3840x2160 GPU decoding works
H.265 10bit 4992x3744 GPU decoding DOES NOT WORK on DaVinci Resolve, but if I open the same file in VLC or Premiere Pro GPU decoding works both on Integrated and on NVIDIA cards. I tested this by disabling integrated card. So the problem must be in DaVinci Resolve side.

H.265 10bit 4992x3744 GPU decoding DOES NOT WORK on DaVinci Resolve

To clarify, it decodes just fine, you just see basically zero GPU usage, all CPU usage and it is very slow.

Vs the 4k which was much faster because it uses the GPU.

H.265 10bit 4992x3744 GPU decoding DOES NOT WORK on DaVinci Resolve

To clarify, it decodes just fine, you just see basically zero GPU usage, all CPU usage and it is very slow.

Vs the 4k which was much faster because it uses the GPU.

Correct, I can playback the footage and it's correct, but choppy (due to lack of GPU decoding).
VLC can playback that footage no problem even on integrated GPU.
I also tried to disable Integrated GPU to force VLC use NVidia and it also works fine and uses GPU decoding.

If I try to make proxies via Davinci Resolve it takes very long and runs only on CPU.
I did the same test on Premiere Pro and making proxies runs muuuuch faster and I see GPU usage.

So from all of these experiments I feel there might be a bug in Davinci Resolve.

Does your 1060 (mobile) GPU have 6GB VRAM? If so then it's at the very bottom limit for working with 4K footage. The FAQs here recommend a minimum of 8GB VRAM for 4K. Your version of 5K footage has well over twice the pixels of regular 4K footage so it's likely that your GPU is simply not up to the task of delivering hardware acceleration in Resolve at that much higher resolution. Puget Systems recommend at least 4GB VRAM for HD, 8GB for 4K and 20+GB for 6/8K.

Comparisons with other software are not really relevant here as they have utterly different architectures. It's a bit like asking the question "giraffes eat leaves from tall tress, so why can't hippos?".

You nearly made me spill my coffee over the keyboard, Bob!

[Rohit Gupta]

CPU Intel i7-7700HQ
RAM 32.0 GB
GPU Intel HD Graphics 630
GPU NVIDIA GeForce GTX 1060 (mobile)
DaVinci Resolve Studio

I have footage from Panasonic GH5:
H.265 10bit 3840x2160 GPU decoding works
H.265 10bit 4992x3744 GPU decoding DOES NOT WORK on DaVinci Resolve, but if I open the same file in VLC or Premiere Pro GPU decoding works both on Integrated and on NVIDIA cards. I tested this by disabling integrated card. So the problem must be in DaVinci Resolve side.

We limit the maximum resolution we decode on the GPU based on VRAM. If we use up too much memory for HW accelerate decode, we will run out of GPU VRAM for compute, display, encode etc. Other playback apps don't have to worry about this.

We limit the maximum resolution we decode on the GPU based on VRAM. If we use up too much memory for HW accelerate decode, we will run out of GPU VRAM for compute, display, encode etc. Other playback apps don't have to worry about this.

Thank You for an answer,
Here is a comparison of Davinci resolve making a proxy out of H.265 10bit 4992x3744 footage vs Premiere Pro:

Davinci Resolve

Proxy davinci resolve.jpg (222.8 KiB) Viewed 2530 times

Premiere Pro:

PPro2.jpg (257.78 KiB) Viewed 2530 times

Render times:
Davinci resolve 02:44
Premiere Pro 00:38

Also Premiere Pro can playback this footage at normal speed without any frame drops, while I can't preview the file on Davinci resolve at all - it's to choppy.

Also notice that PPro uses both GPU's for making this proxy, I'm not sure if it makes any extra improvements or not. But the main GPU memory is used only half way.

So I think this limitation you mentioned is really unnecessary, I would rather have poor performance of the footage if it comes to that compared to no performance (unusable) at all and having a need to switch back to Premiere Pro

CPU Intel i7-7700HQ
RAM 32.0 GB
GPU Intel HD Graphics 630
GPU NVIDIA GeForce GTX 1060 (mobile)
DaVinci Resolve Studio

I have footage from Panasonic GH5:
H.265 10bit 3840x2160 GPU decoding works
H.265 10bit 4992x3744 GPU decoding DOES NOT WORK on DaVinci Resolve, but if I open the same file in VLC or Premiere Pro GPU decoding works both on Integrated and on NVIDIA cards. I tested this by disabling integrated card. So the problem must be in DaVinci Resolve side.

We limit the maximum resolution we decode on the GPU based on VRAM. If we use up too much memory for HW accelerate decode, we will run out of GPU VRAM for compute, display, encode etc. Other playback apps don't have to worry about this.

Could we give users some choice about this?

Best choice is decoding highly compressed media into something lighter. Or a better GPU.

Best choice is decoding highly compressed media into something lighter. Or a better GPU.

Yes and no... If I can playback smooth that footage over my current GPU and I don't need any fancy effects I'm happy leaving it in my timeline as it is.
If it doesn't play smooth enough I would make proxies - in this case I would expect GPU to be used in this process, but as I explained in my previous reply Davinci doesn't use GPU and takes muuuuuch longer to maker proxies compared to Premiere Pro.

Could we give users some choice about this?

Yes, please, don't try to guess what footage is not gonna play smooth on user end and make limitations that make it play soooo much worse.

In my case I can't upgrade my GPU since I'm on laptop. And I'm forced to use Premiere Pro instead of Davinci resolve if I want to use this footage.

We limit the maximum resolution we decode on the GPU based on VRAM. If we use up too much memory for HW accelerate decode, we will run out of GPU VRAM for compute, display, encode etc.

For Proxies and Optimized media this is not a concern though, as nothing else is happening while generating proxies. And the Encode to DNxHR is happening on CPU.

Are you using the Free version of Resolve or the Studio version. I think the free version may have a resolution limit of UHD at least for export not sure about playback though.

Are you using the Free version of Resolve or the Studio version. I think the free version may have a resolution limit of UHD at least for export not sure about playback though.

I'm using Paid Studio version. Free version didn't use GPU decoding at all, Paid version everything is good and smooth up to 4k and above that resolution GPU decoding seems to be disabled for my system.

Could be your GPU that is limiting hardware decoding to 4K. Did you check their matrix?

Could be your GPU that is limiting hardware decoding to 4K. Did you check their matrix?

GPU decoding runs totally fine on Premiere Pro and VLC, only Davinci resolve limits that.
I checked NVidia website and could not find any limitations for my GPU in terms of higher resolution H.265

Same problem with my nvidia gpu. Resolve doesn’t use gpu decoding for my 5.3k 60fps hevc video, while any other software play the video perfectly with gpu decoding.

We limit the maximum resolution we decode on the GPU based on VRAM. If we use up too much memory for HW accelerate decode, we will run out of GPU VRAM for compute, display, encode etc. Other playback apps don't have to worry about this.

There is a situation, where this assumption may be untrue: Multi GPU setups.
My Laptop has two devices with the ability to decode the 5.7k 200Mbit 10-bit 4:2:0 HEVC footage from my Panasonic GH6: The Intel 10th Gen QuickSync enabled iGPU, and the Quadro T2000. I presume the 4gb of VRAM in the Quadro T2000 limits the decode capability to 4k max. Well then let us make the choise to decode only with Intel's QuickSync. Wouldn't that aleviate the issue? The iGPU uses shared memory and with the 64GB installed and according to Davinci with 25GB adressable, this should be a way forward.

GPU choise3.png (86.28 KiB) Viewed 1734 times

Please trust your users a bit more, let us experiment and fall on our noses, if our assumptions are incorrect. I just bought Studio my current project and am fairly dissapointed to see hardware decode disabled for my use-case.

Good morning everyone,
sorry for continuing this old post, but same problem here.

Davinci Resolve Studio 18.5 doesn't use my Intel UHD 620 GPU to decode H265 5.3K GoPro videos.

All other programs (VLC, Windows Media Player, PowerDirector, etc.) have no problems and regularly use the GPU for the same videos.

My GPU has 19.9 GB of (shared) VRAM, but DaVinci Resolve sees only 15.9 GB. My laptop has 40 GB of RAM. I think that this amount of RAM/VRAM should be enough to use the GPU to decode videos.

The result is that Davinci Resolve is unusable on my laptop: the video playback is too choppy to be edited and the creation of proxy media or optimized media is way too slow without GPU usage (yes, Davinci Resolve doesn't use GPU neither to create proxy and optimized media).

I understand the need to limit the usage of VRAM to avoid the out of memory, but in this way the software become unusable on a laptop that is capable to use it without problems.

I hope that will be possible to stretch this limit a little bit, otherwise the only solution will be to switch to another software.

Thank you.

Regards.

Good morning, any news about this topic?

BlackMagic Design, please, can you relax this VRAM limit to allow also who has a mid-range, but capable, GPU to use the product for 4K and 5.3K videos?

Thank you.

Regards.

Good morning, any news about this topic?

No, it seems black magic has set an undocumented limit as to when acceleration happens.

I'm traveling now and have to use my Laptop to cut a video, shot in 5.8k 30fps and 4k 120fps on the GH6. Both h.265.
64gb 10th gen i7 + 4gb Nvidia Quadro T2000 + 64gb RAM.
When 4k 120fps clips are there, smooth as butter, but when the 5.8k 30fps clips come, It's like pulling your teeth out with bare hands, it's just an awful process.

You can't even create proxy media, because the decoding happens CPU only and the Davinci Resolve interface predicts 8 hours for proxy creation. At least if it used acceleration to create Proxy media, but no, it's a hard feature disable with based on an arbitrary limit that was set years ago.
So I found the quick solution to get through this edit without losing my sanity: Have VLC Player open. So I scroll in VLC to find the correct passages and cut them in the edit page with Davinci Resolve.

Luckily VLC Player has a feature DaVinci Resolve did not manage to gain after so many years: Not setting arbitrary limits as to when acceleration is allowed to happen.

edit: Not too sound too negative, Resolve handled itself really really well, editing 4 cameras with a mix of 1080p, 4k and 5.8k with LUTs, Color Grading, de-noising, sharpening and stabilization, parts of footage straight from SD Card, since Laptop's storage wasn't enough. Still, changing the timeline and having to wait 2-10 seconds for the update to be visible is painful, whereas the 4k120p footage updated almost instantly.