Brand new RXP GTN 750 installation 2 days ago, 2.5.26.0

Latest Garmin trainer 6.62.4 / 2710

X-Plane 11.50b14 Vulkan, AMD 2700X 16Gb RAM nVidia 2070

No other plugins installed.

Works beautifully in default Baron and Aerobask DR401 (as pop-up) or Justflight TB20 (as 3D panel or as pop-up). Smooth in DHC Twin Otter (as 3D panel). Also good in the Carenado S340 (3d panel and pop-up).

Horribly slow and stuttery in JustFlight Hawk (as pop-up), this plane come with an .ini file of its own, also stutters in default Cessna and Stinson as pop-up. Stutters badly in the VFlyteAir Turbo Otter (as 3D panel).

I cannot work out why it works in some planes and not in others. Have tried CpuAffinity = 0 -1 and -2 with no benefit

The weird thing is, even in the planes where it stutters in normal screen mode, when I switch to VR (Oculus Rift S) the pop-ups there are absolutely smooth.

 

Edited July 9, 20205 yr by redshift27

Hmmmm. I've just updated to Beta 14 and XP is crashing. Log file blames RXP GTN 750. I've got Traffic Global running so wonder if that's conflicting again. RXP GTN 750 was working fine yesterday with Beta 13 using the workaround of disabling the ai count. Trying different aircraft to see if its a global or specific issue.

 

Quick Update - Now up and running with default cessna, Traffic Global running with TCAS enabled. AI Count disable fix still working - all good so far with B14

Edited July 9, 20205 yr by soppie

Hi,

Have you checked whether these aircraft didn't came pre-configured with GTN set to half-refresh rate setting?

Just open the GUI Settings Panel and look for this one in the 'graphics' section.

Otherwise, this might just be a new bug with XP11.50B14. Can you try the problematic aircraft with XP11.41 instead?

On 7/10/2020 at 9:00 PM, RXP said:

Hi,

Have you checked whether these aircraft didn't came pre-configured with GTN set to half-refresh rate setting?

Just open the GUI Settings Panel and look for this one in the 'graphics' section.

Otherwise, this might just be a new bug with XP11.50B14. Can you try the problematic aircraft with XP11.41 instead?

Nothing to do with half-refresh settings. The lag can be measured in seconds sometimes!

It is indeed present as a bug in 11.50B14 and RXP works fine in 11.41 on these aircraft.

The CPU core on which Garmin presumably runs (guesswork whilst observing behaviour in Task Manager whilst clicking on the GTN) repeatedly maxes out at 100% during the lag.

Thank you for the feedback. It is most likely a problem with their changes in the Vulkan implementation for B14 but we're not experiencing any lag or problem on our tests systems so far.

Because you've vastly different performance depending on the aircraft you're using, but even more importantly whether you're in VR or not, and because they've tried addressing VR performance issues in B14, you might want to file a report:

http://dev.x-plane.com/support/bugreport.html

Your log.txt files will most likely help them because it reports your video card capabilities and other metrics which might help them accessing a possible cause for GTN lagging with the default Cessna.

Please note: some of the aircraft you're using might have their own compatibility issues with XP11.50B14 leading to poor performance, especially if the incompatibility root cause in the aircraft leads the aircraft code taking all CPU available either directly, or indirectly (causing X-Plane to)

 

Edited July 13, 20205 yr by RXP