I do have an nvidia card, but since MacOS 10.14 the nvidia driver manager reports that my driver (387.10.10.10.40.105) is not compatible with my OS, and it also reports that there are no newer drivers available when using the update function. So I'm currently back at the default Apple driver.
I have ran the nvidia driver before MacOS 10.14, and it did feel slightly faster than the driver supplied by Apple. I doubt if it will improve opening an 8K*8K image in a browser though...
