Stuttering Issues on Mac Pro 4,1->5,1 GeForce GTX 960

[nownot]

I have a Mac Pro 4,1 that I flashed to 5,1 and a MSI GeForce GTX 960 using Nvidia web drivers and I've noticed, espcially on screen savers, that the video / dragging a window will stutter. Below is a video that shows the screen saver where you can see the jerky video.

The issues persist for about 30 seconds once I login, then everything seems normal. I was wondering if anyone has any thoughts on what cold be causing this issue.

Thanks

 

[thornslack]

That sounds and looks like a gpu that's running unaccelerated. I wonder if the the graphics driver is taking a moment to kick in. Didn't flashed 7xx cards display this behavior when running on OS X drivers in between nvidia updates? I sorta forget, just spitballing.

 

[nownot]

That sounds and looks like a gpu that's running unaccelerated. I wonder if the the graphics driver is taking a moment to kick in. Didn't flashed 7xx cards display this behavior when running on OS X drivers in between nvidia updates? I sorta forget, just spitballing.

Im not sure how to check if its running in accelerated mode, I do have Nvidia web driver check in the system preferences.

Also want to add that this isn't flashed. Its a generic pc card using the web drivers.

 

[thornslack]

To me it sounds like there's a hand off of drivers occurring. I am really no expert on this, but here's a quote on a similar topic from someone who knows more:

I don't think Sierra has changed a lot beside the moment where the OS driver kicks in, it's just a little earlier now. I'm quite sure that Recovery Partition has always worked with PC GPUs as long as the OS had a driver.


The Mac EFI in a GPU ROM contains (besides other things) an EFI display driver, which provides basic graphics functionality to the EFI. Clover has it's own generic driver, which will bring PC cards to life.

When OS X starts up, it'll load device drivers depending on the device ID of installed PCIE cards. If the installed GPU has an OS X driver, it'll load up and the display output gets handed over from EFI to OS (the opposite happens when shutting down, the spinning wheel is EFI again).
If there's no OS driver, OS X will continue to use the EFI driver for display output. No 3D acceleration and sluggish as hell, but enough to install a driver.

 

[owbp]

I have MSI GTX 980 Gaming 4G and after leaving cMP idle for few minutes (say i have screensaver set to kick in after 10 minutes and i leave cMP idle for 5 min) i have awful lag and unaccelerated desktop for few seconds after moving the mouse. Don't know if it is in any way connected issue, but ill follow this thread for maybe possible solutions.