Comment by Wowfunhappy
18 hours ago
Another possible reason that occurred to me: what if you have VRAM but you're not using it all the time? For example, let's say you bought a GPU because you like to play video games. When you're not actively gaming, you probably don't need 16 GB of VRAM just to render the desktop. Might as well use it for something else, right?
Edit: Although, this is predicated on the system being able to release VRAM that is acting as swap when it's time to start a game. Can it do that?
I am catching up on comments
The reason I wrote this is I run this laptop in hybrid (AMD display + NVIDIA as swap). So all at VRAM was going to waste.
On your question re: switchable swap. It's on my to-do list ;)
Wouldn't this prevent the nvidia GPU from being power gated since it's never "idle"? So like your battery life regresses?
While it may prevent sleep, one of the frustrations I have on an old skylake desktop with a bunch of 1080ti GPUs is that when set to power saving modes, the GPUs sit at 1x2.0 pcie lanes and low wattage. That slows down loading quite a bit.
So it will use more power, but nothing close to when the GPU is being used.
It's easy enough to 'offline' swap space on Linux normally so I suspect that would work fine, as long as you didn't instantly run out of RAM when doing so.
If you have enough swap on disk available, it should be fine.
Best case is if gaming and productivity (with high memory use) activities are not concurrent, and productivity applications are stopped before gaming starts, then `swapoff` can easily release swap device without restart.
> you probably don't need 16 GB of VRAM just to render the desktop
Microsoft: hold my beer