Something lags when no monitor connected to PC

[pancakeslp]

Discord user sinagolakh#2935

i'm connected via lan and on remote play there is not any mouse latency and works smooth and perfectly fine
but when i want to play with hdmi for better quality it has latency and game becomes unplayable

After several discussions it is revealed that sinagolakh will unplug the HDMI cable from his pc to monitor, and instead plug in the HDMI cable from PS4to monitor. As they only have 1 monitor.

So think I can replicate this issue, it feels like there is an intermittent lag somewhere, but I cant pin point it to anywhere specific.

Thoughts

• First assumption is when someone unplugs the HDMI from the pc, the screen might resize because there is nothing to observe this. But when I unplug all monitors and use the input from PS4, the monitor resolution appears to be the same.
• Maybe remove play is polling the PC less because it can detect that the cable is disconnected
• on my computer I get an average number of GamepadProcessor.OnReceiveData requests at 44 a second, and this only differs by .1 (to 43.9) when I unplug the outputs from my computer (to try to replicate what sinagolakh is seeing). I feel this is should be imperceptible, but even if this is the cause i cant make remote play query for inputs more often.
• tried timing the processing time taking to read IO from mouse and keyboard and report it to remote play, and less than 1ms should not be an issue.
• Can we spoof a second monitor? ... that is either unreliable or costly (and 99% simpler just to get a second monitor)

This has got my stumped.

If anyone sees this and has any ideas for a cause with a fix I am interested in hearing.