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by dogma1138 3516 days ago
>If NVIDIA can't be asked to fully support their hardware on Linux, the least they can do is release some documentation so the Nouveau devs don't need to grope in the dark.

I don't disagree in principle, but they've killed it, releasing information to make it work might be a problem for them, and since this thing is no longer supported adding compatibility for older devices isn't a high priority for them.

It worked poorly on many windows machine, it's effectively still doesn't work on Windows 10 [0] and it's been effectively killed since 2014.

[0]https://forums.geforce.com/default/topic/860554/geforce-mobi...

It's also worth noting that NVIDIA couldn't get the darn thing to work on Linux, it's also worth noting that AMD also had/has similar issues with PowerXpress on non-Iris based Intel CPUs, it does somewhat work well on AMD's own CPU's with integrated graphics and it's more modern "APUs".

>Do you have a source for this?

Source for what? under Iris Intel the CPU handles the switching between GPUs not that it works that well, but it doesn't work well on most OSs other than windows mostly due to how the display driver infrastructure is setup and how the composition manager works (even on OSX you still likely to want to use gpu-switch than rely on the OS).

If you want to blame some one blame the OS tbh, if OSX and Linux had proper user mode display drivers like WDDM, had modern display drivers like WDDM and actually had a composition manager capable of using multiple GPUs then there might be better solutions for this.

But overall it works, it does require you to use the proprietary drivers from both NVIDIA and Intel but it works, at least on Ubuntu I never had issues with following a similar guide to this http://ubuntuhandbook.org/index.php/2016/04/switch-intel-nvi... (reading the comments on that guide it seems that it missing an important part which is apt-get install nvidia-prime) So this just works...

To switch between the 2 on demand you can simply use these commands:

-prime-select intel

-prime-select nvidia

On other distros (or if you are not using nvidia-prime) you might need to use /proc/acpi/bbswitch And modprobe/rmmod to do the switching, there are bash scripts online ready to use which are available as long as you have the proper drivers installed.

P.S. Sorta OT but relevant: http://i.imgur.com/Ql1dsZC.jpg

2 comments

EDIT: Since it's been too long bbswitch = Bumblebee (which NVIDIA actually helps also) the open source implementation of prime, both of which also support the older Optimus laptops but ymmv with BB.

Also it looks like PRIME supports synchronization now if you have a distro with DRM support (no not the bad kind ;) https://devtalk.nvidia.com/default/topic/957814/prime-and-pr... so if you are using their currently suggested setup you don't need to switch manually anymore.

Prime and Bumblebee are totally different from Nvidia Optimus. They have to render to render to Nvidia's GFX framebuffer and then copy it to Intel's GFX display framebuffer.

This is much more expensive than hardware implementation of Nvidia Optimus.

No they aren't, PRIME and BB only now support synchronisation which is how it also works on Windows.

It's more expensive on Linux because the DRM on Linux is broken, there is no longer "Optimus" since NVIDIA no longer uses a dedicated chip, you share a frame buffer with the IGP.

PRIME also supports the older Optimus chip laptops, but again this doesn't work that well, but then again these don't work well with Windows 10 either due to the changes to WDDM.