PRIME and PRIME Synchronization

[kacperski1]

PRIME Synchronization seems to have a really bad interaction with Vulkan applications for me. With PRIME sync enabled, running any Vulkan program (such as the cube demo from vulkan-tools, or the PPSSPP and Dolphin emulators with the Vulkan backends) causes an extreme lag on the whole system. The load average spikes up to higher than 6, and there are long freezes between each screen update. There are no issues when PRIME sync is disabled. This doesn’t affect programs using OpenGL, only Vulkan.

OS: Arch Linux
Driver version: 396.54
Kernel version: 4.18.5
lspci | grep NVIDIA: 04:00.0 3D controller: NVIDIA Corporation GK107M [GeForce GT 745M] (rev a1)
Laptop model: ASUS N550lf

Same Issue here, using Ubuntu 18.04 and the 390 driver series and a GTX 1050. I’ve set up the vulkan SDK but running any of the examples makes the system pretty much unusable until I kill it from another tty. Turning off prime-sync fixes the issue (but makes everything tear). I was going to try the 396 driver but it seems the issue still exists there :(

I’ve been toying around with this. The Vulkan samples from Sascha Willems run fine.

I’ve found that running using present mode VK_PRESENT_MODE_FIFO_KHR seems to causes freezes on my system when interacting. The vulkan samples of Sascha default to VK_PRESENT_MODE_IMMEDIATE_KHR if it’s supported. So I hacked my app to do the same thing which fixes the freeze and locking issue.

This seems like a driver issue to me, seeing as disabling prime synchronization fixes this issue.

Could we get an update on this issue? It’s been a few months already and it still renders Vulkan apps with v-sync completely useless with PRIME synchronization on Optimus-powered laptops.

I’m experiencing it with a Clevo N850HK1 with 1050 Ti Mobile (Manjaro, Liniux 5.2, driver 430.40).

The vkcube package from vulkan-tools is confirmed to replicate the issue. I have two external monitors - one connected through DisplayPort and one through HDMI, but it definitely was happening with just a one external monitor on HDMI. I can’t test without external screens right now, but I think others have had this problem without additional screens as well.

lspci output: lspci output for NVidia dev forums - Pastebin.com
inxi -Fxxz output: inxi -Fxxz output for NVidia dev forums - Pastebin.com