GPU VRAM, or "vram" as I wrote lol. I'm aware they're two different things, what I'm asking is in what actual specific task during a video editing workflow having 16 gigs is going to matter vs having 8 gigs. Because I've used my machine for years to work on 4k videos for wedding clients and my graphics card is rarely the bottleneck as most of the time intensive tasks are using the CPU heavily (according to the Activity Monitor).
I think maybe I replied to this in the wrong thread or something because I remember writing a long response to this, where I also apologised for misreading before
But it definitely happened somewhere; also had an exchange with
@pldelisle about his 2:1 rule, where we discussed how it doesn't necessarily always apply but can be fine as a rule of thumb.
In any case; I will rewrite the main point of that message.
It's not just about the amount of VRAM. The only way to get the 5700 XT GPU in the iMac is with 16GB of VRAM. With 8GB you can get the 5700 but it would not only be a difference in VRAM but also GPU performance, and I'd say that for most tasks that would make the bigger difference. - Some tasks can heavily benefit from the additional VRAM, like some large computer tasks, for example machine learning training, or large 3D modelling projects, but for the most part I advice the bigger GPU for the more powerful processing unit, not the extra VRAM.
And as for what in a video editing workflow can stress it; Multicam, effect rendering, compositing, vfx; All of this also depends on what codecs you edit
I pushed my last 5K iMac to its knees many times, always the GPU was the first to bottleneck and that was the top-end at the time, R9 M295X. Try and make a Multicam clip with like 3 angles, and then retime it to either half speed or double speed or something like that, and try playing it back in the timeline; Maybe overlay some Motion vfx on top, a few layers of colour correction; I'm sure your GPU will be hit hard
