Re: xps 9650 lagging streaming is it a Flash or a Nvidia issue ?
From my experience, if I leave firefox up for more than 5 hours, everything I do becomes freeze-frame, even typing into form fields or text areas. Prompting a restart of firefox. Diagnosis: Your typical Object Oriented Lunacy, probably bloated itself to 8gb of ram or more and started using swap space to even exist.
Flash videos do work well when you start up firefox, for about 30 minutes, at which time they start with their freeze-frame behaviour.
Youtube, since they moved to HTML5 video seems to work better though yeah.