Reverse PRIME Now Works Nicely On Ubuntu 24.10

[phoronix]

Phoronix: Reverse PRIME Now Works Nicely On Ubuntu 24.10

For those making use of "reverse PRIME" setups where you have a primary NVIDIA discrete GPU while monitors are connected to Intel integrated graphics as the secondary GPU, such configurations should be working nicely with the upcoming Ubuntu 24.10 release under Wayland. This support is also likely to be back-ported for Ubuntu 24.04 LTS...

https://www.phoronix.com/news/Ubuntu-24.10-Reverse-PRIME

[FireBurn]

I've been having some issues with regular PRIME lately, basically it's using the iGPU VRAM until it comes full (512mb which I can't change) then slows right down to where the desktop becomes unusable

[pWe00Iri3e7Z9lHOX2Qx]

The Reverse Prime name makes me think of display outputs hooked to the dGPU and rendering things on-demand on the iGPU (which obviously wouldn't be a common thing).

[lem79]

I've been having some issues with regular PRIME lately, basically it's using the iGPU VRAM until it comes full (512mb which I can't change) then slows right down to where the desktop becomes unusable

I have an AMD Ryzen 5700U laptop which had 512mb allocated to the iGPU, and I was able to change it with UniversalAMDFormBrowser (no controls available in BIOS) .. not sure if you have AMD or Intel, but maybe there's an equivalent tool?

[joaquinvacas]

I have an AMD Ryzen 5700U laptop which had 512mb allocated to the iGPU, and I was able to change it with UniversalAMDFormBrowser (no controls available in BIOS) .. not sure if you have AMD or Intel, but maybe there's an equivalent tool?

Wanted to do that on my Elitebook 845 G9 (6650U) as VRAM outage is a real thing.
But it seems is unsupported. Shows an empty menu and firmware only shows 256 or 512MB.

"Yeah but that's not the way dynamic VRAM works and..."

I totally understand that and there is a real benefit on having a locked portion of your RAM to your iGPU so no memory pressure situations could hurt performance.

[bkdwt]

This is great! Now I can use the UHD 630 to render the desktop etc on Wayland and the A2000 to games or softwares then needs GPGPU.

[pWe00Iri3e7Z9lHOX2Qx]

This is great! Now I can use the UHD 630 to render the desktop etc on Wayland and the A2000 to games or softwares then needs GPGPU.

You use case sounds like regular prime, which has worked for years.

[bkdwt]

You use case sounds like regular prime, which has worked for years.

I never see this work on my ThinkCentre.

[Jabberwocky]

Thanks Daniel! Many laptops only support gsync via a single port. It makes sense to have reverse prime for that reason.

I've only had bad experiences with Optimus/Bumblebee/Prime in the past ~14 years but I'm hoping that it changes with my latest attempt this year.

2011 Dell - Sandy Bridge with 560M. The experience was so bad I had to disable the dGPU. Optimus didn't work and Bumblebee was in it's infancy.
2017 Lenovo - Kaby Lake with GTX 1050. Experience was better but battery life was so bad I had to switch to a different system.
2024 Asus - Zen4 with RTX 4070. Hoping this time around it's a good experience in Linux. All Asus zen5 laptops had soldered RAM so far

If this doesn't work out I'm back to System76 / Dell with APU only.

I'm keeping an eye on Asahi Linux as well, it's sad that Apple Silicon is so heavily locked-down. The re-sell value on Apple hardware justifies the extreme prices one pays. Many new laptops cost a fortune and sells for peanuts when you're done with it. I just can't get myself to use their software after kernel lock-downs in macOS 10.15 Catalina.

[QwertyChouskie]

I've been having some issues with regular PRIME lately, basically it's using the iGPU VRAM until it comes full (512mb which I can't change) then slows right down to where the desktop becomes unusable

What processes are using the VRAM? Check the VRAM column in the Processes section of Mission Center.