I don't know how a Dell XPS has a worse DPC latency than any other computer,
oh, it's a long story. many things affect DPC latency, software and hardware. at first Dell thought that it was a software problem and promised to customers it will solve it. but some years after it appeared that they just cannot fix it.
this said, bad DPC latency isn't specific to Dell or nVidia, it just happens sometimes.
Regarding nVidia drivers, it isn't the fault of Windows then, it's the fault of badly designing drivers by other manufacturing of hardware you are using in your computer.
yeah, but my main point was: there's some hardware in Windows world that you just cannot use for realtime audio. if you buy a laptop with nVidia it's not possible to swap this card for something else (and in some cases you cannot disable it). so my advice was to google DPC latency on the exact configuration OP's eyeing.