Nvidia beta driver 370.23 has initial support for PRIME Synchronization

Nvidia has released the beta driver 370.23, the good news for multi-GPU users is that it features initial support for PRIME Synchronization.

Feature highlights for the 370.23 driver:

Quote-Added the ability to over- and under-clock certain GeForce GPUs in the GeForce GTX 1000 series and later. For GPUs that allow it, an offset can be applied to clock values in some clock domains of all performance levels. This clock manipulation is done at the user's own risk. See the README documentation of the "CoolBits" X configuration option for more details.
-Fixed a bug that prevented Vulkan applications from presenting from multiple queues to the same X11 swapchain.
-Added the "PixelShiftMode" MetaMode option, enabling support for 4K and 8K pixel shift displays. See the README for details.

Now onto the beta stuff

For those that don't know, PRIME is a way of enabling you to offload applications and games from one GPU to another. So, instead of a game using your Intel GPU, it would use your better Nvidia GPU.

From what I understand, VSYNC was broken for people with multi-GPU setups like Optimus. This is set to change as outlined in this Nvidia forum post.

QuoteUp until recently, the Linux kernel and X server lacked the required functionality to allow the dGPU and iGPU drivers to communicate and synchronize the copy with the scanout. Because of this limitation, there was virtually nothing any one driver could do to provide the necessary synchronization; it required improvements to the greater ecosystem.

Over the past many months, I've been working to implement and upstream the necessary improvements to the X server and iGPU kernel and userspace drivers so that we could leverage them from within our driver. Finally, they have landed (http://www.phoronix.com/scan.php?page=news_item&px=Xorg-PRIME-Sync-Double-Buffer). Unfortunately, the changes required breaking the binary interface (ABI) between the X server and its drivers, so it may be a while before it propagates to mainstream distros.

This is fantastic news for laptop users with Optimus. Having a smooth experience with game is quite essential, as screen tearing can be a serious nuisance.

The sad news is this part:

Quote"Offload" attempts to mimic more closely the functionality of Optimus on Windows. Under normal operation, the iGPU renders everything, from the desktop to the applications. Specific 3D applications can be rendered on the dGPU, and shared to the iGPU for display. When no applications are being rendered on the dGPU, it may be powered off. NVIDIA has no plans to support PRIME render offload at this time.

So while they have no plans currently to allow it to work like it does on Windows, being able to have a tear-free experience when you select the Nvidia GPU is still significant a step forward for us.

Having to log-out when you switch GPU is annoying, as I tested on a laptop recently, so I do hope one day Nvidia looks to make it work like it does on Windows. It would make our lives easier for sure. Article taken from GamingOnLinux.com.