What CPU do you currently have in your XPS-8930, that you would be contemplating a swap? Normally, a Dell computer BIOS only contains micro-code to allow certain CPU chips to work-properly. They are the ones it originally shipped with and should be listed in one of the PDF manuals.  
Does anyone know if Intel Core i5-9500F might work on the Dell XPS 8930? I know it's not on the list but not sure why it wouldn't work? Would it be due to the wattage difference?  
XPS 8930, Intel i5-9500F compatible?