RE: Precision M4800 : Input lag at log in, Switchable graphics not functioning, GPU fan "chirping" when it starts up.
It looks like a number of people have posted in this thread about a 4k screen model not working, not having the option in bios, and so forth.
Because of the way dell designed the graphics pipelines and the type of display connection used, on the 4k models GPU switching is NOT physically possible, and was never claimed as a feature. Many many consumer product reveiw websites state this, and so did the dell configuration page.
also see this article here > www.notebookcheck.net/Review-Dell-Precision-M4800-Notebook.104416.0.html
"The Precisions generally feature AMD's Enduro or Nvidia's Optimus technology to switch between the energy-efficient processor graphics and the dedicated professional graphic depending on the task. However, the integrated Intel HD Graphics 4600 cannot be used due to the QHD+ screen installed in our review sample and is disabled. This naturally has an impact on the power consumption, which is much higher with a minimum of 19.6 watts than that of a system with an enabled Intel graphics."
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