9800X3D Lag Spikes in VR using Pimax Crystal (video)

So it’s been a frustrating experience so far with the 9800X3D. I tried to troubleshoot some issues with it in this post thread:

Everyone was very helpful and I was able to increase my performance with a few tweaks, but when it came to VR, the situation went south fast. I was so disheartened that I did the last thing I wanted to do, put the 7800X3D back in. Before I took the 9800X3D out, I screen recorded 2 videos. One is a replay of a flight using VR, the other is a VR cockpit video where I tried to follow mostly the same path. After reinstalling the 7800X3D, I recorded the same videos expecting the same results. You’ll see in the videos that the 9800X3D produced
massive lag spikes compared to the 7800X3D, to the point of making it unplayable in VR (at one point the lag was so bad that I was thrown out of the cockpit). One video is posted below and I will upload the other shortly.

System Specs: Gigabyte X670 Gaming AX, 9800X3D, 4090, 64gb ram 6000Mhz Expo enabled No OC

BIOS update F32d AMD AGESA 1.2.0.2a

Gigabyte Chipset drivers for the X670 motherboard 6.10.22.027 and 24.10.24.240625

AMD Chipset drivers for X670

Nvidia Driver 566.14

Full clean install of Windows 11

980 MB/s Ethernet

Graphic settings in MSFS:
TAA
Render Scale 80
AMD Sharpening 100
Reprojection Mode Off
World Scale 100
Nvidia Low Latency Off
TLOD 115
Off-Screen Pre-Caching HIGH
Terrain Vector Data HIGH
Buildings HIGH
Trees MEDIUM
Grass and Bushes MEDIUM
OLOD 105
Volumetric Clouds HIGH
Texture Resolution ULTRA
Anisotropic Filtering 16x
Texture Supersampling OFF
Texture Synthesis ULTRA
Water Waves HIGH
Shadow Maps 768
Terrain Shadows 256
Contact Shadows MEDIUM
Windshield Effects ULTRA
Ambient Occlusion MEDIUM
Cubemap Reflections 192
Raymarched Reflections OFF
Light Shafts OFF
Bloom ON
Glass Cockpit Refresh Rate High

All traffic OFF
Weather Preset Few Clouds at noon
Data Rolling Cache OFF

Pimax Play settings:
Lighthouse
90Hz
0.75 Render Quality
FFR Off
Locked to Half Frame Rate

OpenXR Toolkit settings:
Turbo Mode ON

Things I’ve already tried:
Rolling back the Nvidia Driver
Reinstalling Pimax Play software and rolling back versions
Reinstalling CPU with better thermal paste
Adjusting settings in MSFS and Pimax Play
Taking 2 sticks of RAM out (I have 4x16Gb DDR5 6000)

This post isn’t to complain, it’s to see if anyone here has experienced this issue and may have a solution. I’m not quite ready to give up on the 9800X3D, so asking anyone if they have any other solution that I haven’t thought of that might be able to explain why my performance is less than my 7800X3D.

VR Flight replay external view.

I had the same results. Saw an increase in FPS on monitor. FPS same for both my 7950x3d and the 9800x3d in VR. Did not have stutters but no real improvement in performance to justify the expense. I returned it.

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From the fps window, it doesn’t appear the CPU is the issue. The rdrthread is the limiting factor followed by the GPU and the CPU is last. As a matter of fact I can see the 9800x3d frame times are actually better than the 7800x3d frame times (as I would expect). My interpretation of rdrthread is a lot of objects that the sim is processing most likely from some 3rd party package. Going fast and low probably aggravates the issue.

Apologies in advance if you’ve already gone over this but have you tried a different plane and/or emptying your community folder?

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Just wondering if your bios has the GPU lane set to auto, 5.0, 4.0, 3.0? I am assuming it was unchanged when just swapping out CPUs so maybe of no help. I did see some other thread about someone who had to manually fix the GPU lanes in the bios to fix stutters. such as was set at 4.0 but the riser was 3.0 only etc.

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I have tried different planes and the community folder is empty as it’s a fresh install. Same results each time.

I haven’t heard of this. Could you provide more details or a link to the post? Sounds like it might make a difference with the stuttering issue.

This and motion reprojection don’t play well together. See: OXRTK Turbo Mode, second bullet point

As such, I recommend turning Turbo mode off.

SOLVED!

Thanks to user motoadve, he got the answer on Tom’s Hardware. BIOS default, Clear CMOS. Runs perfectly now!

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Great news, any chance of a Performance overlay video?

bios set to default then save then clear CMOS, not keep at default settings at end?

I will post a video with the updated performance when I get a chance. Suffice it to say for now it’s vastly improved.

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BIOS to default, turn off and unplug computer, clear CMOS (mine was a button on the mobo pressed for 15sec). On boot it should show CMOS reset. I went back into BIOS and reactivated EXPO only. After that everything ran smoothly on MSFS.

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I just bought the 9800X3D. So great to hear you ended up being happy with it :slightly_smiling_face:

Do you know which previous setting(s) in BIOS caused the issue before you reset everything back to default except for EXPO?