VRAM for 8K Color Grading on 8K Timeline

Hi, I wanted to ask if 16gb of VRAM would be sufficient for heavy color grading 8k raw footage on an 8k timeline in Resolve Studio 17? Due to portability I may not be able to go beyond the 16gb and wanted to make sure this would be sufficient before making a hardware purchase decision, as I'd imagine 24gb or 48gb would be best. I know there can be many variables and also the length of the project may not be as important, however just for reference each project would be a total of a 5 min clip on average.

If there is concern for the amount of VRAM being too low what workarounds would you suggest to fit everything inside of the the 16gb without sacrificing quality? Grading on proxies or a lower timeline may not be the best as I have heard that a grade on lower res HD format will also look different once converted back up and also not give you as much headroom if needed as the 8k timeline. Thanks.

A single frame is about 200 MB, so...

A single frame is about 200 MB, so...

So 512Mb vram should suffice? The only direct tie between resolution and vram is ”more needs more” but quantifying it without tests is a guessing game at best. 8K RGBA full float image is around 540MB.

8K is 4x the data volume of 4K, so you could take your current vram usage at 4k, multiply it with 4 and get an estimate. Also divide fps with 4 to get speed estimate. Proxies will not help you with out of mem errors because you still need to render it out at 8K in the end.

Thanks for your replies. If this is the case then it seems like 48gb would be the best bet to ensure that I'd have enough. I would not likely be doing the final grade but would be working with another colorist and wanted to give them the flexibility of picking up where I left off or either starting from scratch if they chose to. Would splitting up the 8k clips into smaller segments and then saving the separate Resolve projects to be compiled together into a master project by the other colorist work?

No, that doesn't help. Resolve is not loading your whole movie into the VRAM, but when doing temporal processes, like NR, optical flow or the like, it'll load quite a few frames.
And caution: VRAM doesn't add up, it needs to be in one card! So, good luck finding any card to buy at this time…

For working with 8K, you will need at least 24GB of VRAM. I work with 8K and tried it with a Nvidia 2080ti. While it would work SOMEWHAT, I was constantly getting out of GPU memory warnings. Also, Fusion wasn't usable at all, as it would crash almost immediately. The 2080ti had 11GB of VRAM. A few months ago, I switched to a Nvidia 3090 which has 24GB. My system is only a year old and was built by Puget Systems. They probably do more NLE specific system testing than anyone else I'm aware of. Their recommendation for 8K with Resolve is 24GB or greater. Since I switched to the 3090, I no longer get GPU memory full warnings, and have no crashes with Fusion. In fact, I haven't had any crashes at all.

I would suggest that you go to Puget Systems website and look at their articles and recommendations for Resolve.

Thanks guys, yeah there is only one card that currently has 48gb of VRAM and I don't think it's able to fit inside of the portable desktop replacements so that would be out right now. There's a specialty laptop with a card that has 24gb of VRAM but the cpu is laptop-based so I guess I'd need to get two pc's, one for desktop duties for my other stuff and then the laptop for the color grading in Resolve. But thanks again for all of your help.

If you're not delivering 8K and you don't have an 8K monitor to see your work, then you don't have to have work on an 8K timeline.

And if you are actually working and delivering in 8K you'll need a built to spec desktop and not a laptop.