VR Performance tanked AGAIN after installing a SECOND 4090! How to troubleshoot?

Continuing the discussion from Performance tanked after installing (?) 4090!:

After trying the suggestions made in response to my post above did not solve the problem, I returned the 4090 and requested a replacement. The replacement came yesterday and after a couple of failed boots, in seemed to have installed OK. As usual, I first ran Time Spy and the results were everything I’d hoped for my: system went from 18349 to 25416.
User Benchmarks were also good:
UserBenchmarks: Game 351%, Desk 109%, Work 330%
CPU: AMD Ryzen 7 5800X3D - 107.4%
GPU: Nvidia RTX 4090 - 340.9%
SSD: WD Black SN750 NVMe PCIe M.2 1TB (2019) - 247.6%
SSD: Adata SU760 512GB - 101.8%
RAM: G.SKILL F4 DDR4 3600 C16 4x8GB - 129.3%
MBD: Gigabyte GA-B550 AORUS ELITE
Second 4090

I first tried a 2d MSFS flight using GeForce “Optima;” setting and it was superb. But when I tried VR, it was as described in my previous post: so slow you couldn’t possible fly. I tried again after removing the optimal settings (thinking they probably only applied to 2d and got the same poor performance.

This morning I resumed my attempts to find out what’s going on and I ran Time Spy again: the result: 1203!! Approximately 5% of my previous score! The Kombuster score also tanked to 968 and 15 FPS.

I cannot fathom this. How can changing the GPU causes such radical changes in my system? Even further, how would I go about trouble shooting this? I am at a complete loss and would (as you could imagine) be extremely grateful for and assistance.

I just checked HLA and, as expected, it’s performance is severely degraded also. It’s a though a single run of a VR program causes some permanent degradation in my system.

My first areas to check would be…

  1. Power supply. Since things are working, but slowly, wondering if the GPU is getting enough power. Can you try reconfiguring the PCIe power cable setup going to the card? (Different ports on the power supply, if it’s modular? Or just swap around the PCIe cables into the adapter.)

  2. Flatten the system: Back up your data and reinstall Windows from scratch. I’ve had horrid MSFS performance problems solved by just rebuilding the OS and MSFS install from scratch.

Something’s definitely awry, given the 2D perf is an issue too. Maybe use a utility to see how much power is going to the GPU?

Sounds like your system may be trying to install your old drivers (or their parameters) … reinstalling Windows from scratch is what I would do.

I also have a 5800x3D paired with a 3090 and an HP Reverb G2. I was also experiencing subpar performance in VR. Two settings changes made the most difference. I observed 10-20 fps improvements. I am not something you would see the same.

I disabled both virtualization(SVM) and multithreading (SMT) in my bios. Disabling virtualization led to the biggest performance gain.

Good luck.

First, thank you to those who responded. Unfortunately I find myself in the same situation again and I’d like to tell the story on the chance it might provide more information. Even before I read some of the suggestions, I contacted Gigabyte technical support an had a very unsatisfying conversation: the tech insisted that the problem was my 850 watt PSU and that since the 4090 is rated for 1000 watts I had to upgrade my PSU. In spite of my pointing out multiple inconsistencies in this formulation, it became clear that I would get no further assistance from Gigabyte so I installed a 1000 watt PSU but thereafter my PC failed to boot. So back to the shop where the tech himself called Gigabyte and even after rectifying the PSU problem, he got no help either.

He tells me it got a Kombuster score over 4000, but after only performing a minor Windows upgrade I run Time SPY and get another ridiculously low value of around 4000, a fraction of the best value the 4090 has produced of 25,000. None the less I then tried MSFS and had possibly useful results.

I first ran it in 2D, with no VR connected and used the Nvidia recommended settings. It looked pretty good! Pretty smooth and mostly Ultra settings with DLSS. Encouraged, I then plugged in my G2, and I IMMEDIATELY noticed degraded performance of my PC even while NOT running any game. In any case, sure enough MSFS in VR was absurdly bad, running in seconds per frame, and a quarter to half the image almost always blacked out.

At that point, I did do a reinstall of Windows, in a last desperate hope, but unfortunately that didn’t help either. I know this is long winded but I’m hoping it will suggest some possibility to someone because I see no possible routes to resolution at this point. Take it to a different shop? Support from Gigabyte? Give up on the 4090? All unwelcome alternatives.

P.S., On the remote chance this will help some “computer whisperer”, some additional strange behavior:

First, once something (whatever it is) goes wrong, it effects ALL VR games, not just MSFS.

It also affects 2D performance, at least in MSFS.

It affects booting. Frequently, almost inevitably the system will fail to boot. It will sound like it is, fans speed up then slow down, but no display.

Sometimes when this happens disconnecting my headset will enable the system to boot and sometimes I have to disconnect the headset AND my monitor (both connected via DP) and connect the monitor via an HDMI cable and it will then boot. That’s how I got here now after the latest round of such problems booting.