PSA & Request: Graphics Amp + VR + Monitors = Slight Frame Drop

Hi guys,

So, I've come across an interesting problem.

I use this setup:
17" AW R3
Graphics Amp w/ GTX 1080
Dual U3415W Dell Monitors
VR (Vive and Rift - one at a time via hdmi)

Using Vive or Rift, I've noticed frame drops every ~8 seconds from 90hz to 75hz for a few frames then go back up to 90hz. This is fairly consistent across all VR games no matter the complexity.

I was able to find the culprit, by disconnecting my dual monitors from the amp and run purely off the laptop display only with the VR units attached via the AMP then everything runs at 90hz no problem.

This problem was also with my 980TI and old nvidia drivers (I've updated w/ the 1080 to the latest). I originally thought the 980TI was being taxed... apparently it was not.

I've submitted a bug report to nVidia as I'm fairly convinced this might be a driver bug. It even happens with 1 external monitor connected as well. And yes, there are no other applications running, services, etc that would be causing this... I've run in a basic startup mode to test this conclusion.

I'm curious to know if anyone else has a similar setup, in terms of any AW laptop (Any Size) + GA (Any Card) + external monitors (One or Dual) + VR system (Vive or Rift) and could help test my hypothesis as well. Easiest way I found to see it happening besides looking at the Vive frame reporting tool is to just throw FRAPS on the PC application of a Vive or Rift app and you will see the frame counter. I see it clearly drop from 90 to 75... sometimes 90 to 85 or 80, but still drops every 5-10 seconds.

Thanks!

 

Curious, if you had two external monitors connected you'd get frame drops. What if you only had one external connected? Same thing?

 

Yes, same issue even with 1 monitor and it wasn't any better/worse which is why I really think it's a driver issue. I talked with nVidia and they explicitly told me there's nothing they can do. They said I'd have to talk to Dell (haha). They also directed me to a page that said, while the GA does work with VR, it's not officially supported by anyone.

I have to turn the monitors off via the windows monitor tool to use my headsets, not a huge deal... but annoying none the less. Or I live with a few frame drops here and there. I bet some people wouldn't notice, but I do.

I'm surprised nobody else responded here, I guess not many people have the GA + VR headsets and frequent these forums.

 

Yea I'd contribute but entering the VR arena is very expensive. Need a beefy external card before even buying the headset. Impressed you own both rift and VIVE.

 

I was going to say, NVIDIA is terrible. They refuse to acknowledge any bugs at all and send you in circles. Looks like you've already experienced that. Unless you have a direct contact an NVIDIA level 1 just gives you the finger.

 

@LVNeptune ,

Actually, I went through their bug system and I had a great experience with them. They didn't solve my issue, but they did ask me questions and we had a good 3 to 4 email exchange. Don't use their forums because it's a ghost town in there, in my experience.

Here's their last response to me, which I wasn't thrilled with the outcome, but very happy with the support:

"Thank you for contacting Nvidia Customer Care. Currently Nvidia, HTC, and Oculus don't support the use of VR with XGPU's or External GPU's. If we try this scenario without the XGPU then we do not see this bug. I think the fact that it works as intended without the other monitors connected is fantastic. Unfortunately there is nothing else we can do here as there are limitations in the way the hardware works.
You can see here in the Q,A, That they say it is not supported but still works. You may be able to report this to Dell but I do not know if they will be able to fix this as it is likely a hardware limitation with the XGPU.

https://na.alienwarearena.com/groups/vr-alienware-graphics-amplifier/
"