How to get Resolve to choose the right GPU?

Disregard my signature specs. I have a new Windows machine that has 2 GPUs, a 980 Ti and a 1080 Ti. After installing the new 1080 Ti, my playback performance seems very similar to the 980 Ti when I had that card by itself. How can I make sure Resolve is using the 980 Ti for the GUI and the 1080 Ti for processing/rendering? I have both my displays physically plugged into the 980 Ti, figuring then Resolve would choose that GPU for processing, but according to my GPU monitor in Task Manager, most of the load is falling on the 980 Ti still. Any suggestions?

Currently the GPU selection I manual, both GPUs are selected and set to CUDA.

GPU load.PNG (8.02 KiB) Viewed 1187 times

[Peter Chamberlain]

Only connect UI monitors to one GPU is the only way.
Try them on the other.

Only connect UI monitors to one GPU is the only way.
Try them on the other.

Thanks for the quick reply! That's what I thought, which is why I had the monitors only connected to the 980 Ti. Instead of manual selection I tried "auto" and that seems to have helped. Now the 1080 Ti is taking the load and my playback is smoother in parts where it dropped frames previously

GPU load w Auto select.PNG (5.63 KiB) Viewed 1180 times

How does the "auto" feature choose which GPU to use for what?

[Peter Chamberlain]

Auto does not pick GPU, it defines which GPU language to use.
Only connecting the ui monitors define which is used for ui

Then u can choose to also use it for image processing as well or not

Ok, I guess I am not sure then how to optimize my system for Resolve. I have a 16-core 3.4ghz threadripper, 64GB RAM, a 980 Ti and a 1080 Ti and a 8TB RAID composed of 2 6gbps sata drives and at 4K, with a simple color correct and text, I am getting dropped frames. My windows performance monitor says the disks are operating at 60 mb/s each (capable of 300+), my CPU usage is low, my 980 Ti usage is almost nothing and the 1080 Ti load is around 30%. Others have built systems with the same specs and same parts and were able to play 8K ftg in real-time without a proxy resolution. So what am I doing wrong here? Is Windows unable to get the same performance from ProRes files as on the Mac? Even some 720p h.264 files scaled up to 4k are very jittery. So Im not sure why Im not getting better performance? Any ideas?

On one shot where I was consistently dropping frames I removed the temporal NR and then it went right up to 24fps playback, but that doesnt necessarily explain the other instances. Sometimes even zooming in on a still image can result in dropped frames.

[Peter Chamberlain]

What NVIDIA and what CUDA drivers are you using for your mixed GPUs?
If you use BMD disk speed test, what speed does it show?
Ignore h.264, test with dpx files to prove max performance.
Then deal with decompression workload.
and for 4K, are you talking 24fps, or 60?
Do you have a DeckLink installed and if so, which one and what version of Desktop video.

Someone might be able to guide you with this info.

Hello! I want to ask which configuration will be better for better performance. My computer is the following features: Intel i7-8700k, 32 GB DDR 4 2666, 250 gb ssd system, 8tb hdd for video, 3tb hdd for cache, nvidia gtx 1080 8gb Evga. I work mostly music video clips in 4K resolution, installation and color corrections. I use davinci resolve 15 studio beta 5. I would like to improve productivity. My question is whether to add another 32 GB ram or another sli card?
Thanks!

Изпратено от моят LG-H815 с помощта на Tapatalk

What NVIDIA and what CUDA drivers are you using for your mixed GPUs?
If you use BMD disk speed test, what speed does it show?
Ignore h.264, test with dpx files to prove max performance.
Then deal with decompression workload.
and for 4K, are you talking 24fps, or 60?
Do you have a DeckLink installed and if so, which one and what version of Desktop video.

Someone might be able to guide you with this info.

1080 Ti Drivers: 398.11
980 Ti Drivers: 398.11

I believe the CUDA drivers are included with the Windows drivers right? The only other CUDA drivers there are is the toolkit which seems like its for developers.

No BMD Disk speed test for windows. The ATTO disk speed test shows 330mb/s from the RAID.

I have primarily 4k ProRes 422 footage. I dont recall the exact resolution but its the 4K DCI Scope I believe. 24fps. No decklink. No Desktop video installed. Just playing back in Resolve.

So I got Resolve to improve playback performance by about 30%. Overall much better, not perfect, but much better. I did this by enabling the GUI GPU to compute as well. Before this option was either not there or I was unable to enable it, because I checked.

So things are better, but I am now wondering about mixed GPU performance in Resolve. Will the 980 Ti throttle down the 1080 Ti? Or have I got things setup for best optimization?

Wow, I just noticed it changed GPUs. The 980 Ti used to be GPU #1 and it said - GUI by it. Thats when I selected use display GPU as compute (thinking it meant the 980 Ti). Now the 1080 Ti is card #1 and neither says GUI by it. This GPU stuff in Resolve is so confusing.

GPU Settings.PNG (21.53 KiB) Viewed 1058 times