Use your Nvidia GPU's VRAM as swap space on Linux

Re:Use your Nvidia GPU's VRAM as swap space on Linux by Wowfunhappy on Tuesday June 02, 2026 @08:45PM (#48378222)

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?

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by Saris on Tuesday June 02, 2026 @09:38PM (#48378719)

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.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by eru on Wednesday June 03, 2026 @12:30AM (#48379913)

If you have enough swap on disk available, it should be fine.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by c0dejedi on Wednesday June 03, 2026 @12:54AM (#48380057)

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 ;)

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by kllrnohj on Wednesday June 03, 2026 @09:38AM (#48383899)

Wouldn't this prevent the nvidia GPU from being power gated since it's never "idle"? So like your battery life regresses?

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by nyrikki on Wednesday June 03, 2026 @01:58PM (#48387392)

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.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by tremon on Wednesday June 03, 2026 @03:14PM (#48388498)

Is VRAM not directly accessible by the system then? Since it's mapped directly into the CPU's address space, I had assumed that there's a simple DMA controller managing said access and I would then also naively assume that said controller is separate (or at least on a separate power plane) from the actual GPU.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by kllrnohj on Wednesday June 03, 2026 @04:22PM (#48389439)

they are talking about the scenario of having a discreet GPU in addition to the GPU on the CPU. So there's 2 GPUs, and the nvidia one has its own VRAM (typically of the GDDR variety even) that isn't shared with system RAM (hence the purpose of this project). So that also means 2 memory controllers.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by qingcharles on Wednesday June 03, 2026 @04:04PM (#48389225)

Good point, you might wanna disable it on battery, but I'm guessing a lot of people have their laptop plugged in practically 24x7.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by nuccy on Wednesday June 03, 2026 @03:19AM (#48380948)

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.

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by ornornor on Wednesday June 03, 2026 @08:24AM (#48383051)

> you probably don't need 16 GB of VRAM just to render the desktop

Microsoft: hold my beer

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by p_l on Thursday June 04, 2026 @03:58AM (#48395564)

You mean Chrome? (Looking at the 5GiB usage here...)

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by Wowfunhappy on Friday June 05, 2026 @07:58AM (#48411208)

Google Chrome is using 5 GB of VRAM?! Are you running something with WebGPU or something?

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Re:Use your Nvidia GPU's VRAM as swap space on Linux by p_l on Friday June 05, 2026 @09:14AM (#48412058)

It's called prerendering tabs or something :V

At 4k it adds up, especially since if you look into DevTools Chrome actually renders more at least vertically if not across major scroll regions.

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