- Edited
No, your hardware is more than enough to handle the video above 5k. It's just DeoVR has some difficulties handling the 10bit video output. If you transcode the video from 10bit to 8bit, even 8k videos will play smoothly. I think this is a pipeline issue, because the decoder is only working at 60% for 10bit videos, not 100%. Something in the pipeline has cause the traffic to slow down and the decoder didn't get the full data to decode in time.
Oh, there is a little fix too. If you are using LAV video decoder, uncheck the "P010" in "Output Formats" will help a little bit. This way, it will force LAV decoder to decode the video in 8bit format, but still, probably won't help enough.
I only have a Geforce 1080, so the result might be different.