Not necessarily...the device manager will not recognize a device without the appropriate driver installed, I recommend getting those drivers from the video card manufacturers website and report back. People here love to help.
Have you used or seen a 14" laptop at 1080p resolution? A 27" monitor running 4k would have similar font size. I agree a 27" 4k monitor would be to small for day to day use. But a 4k 40" inch would be acceptable, it would be same font as 1080P 20" monitor, and larger than 17.3" 1080p laptop. However, not recommended for ppl with bad eye sight, use common sense.
Finally you are agreeing with me, I thought it would never happen. Awesome. So yes, in summary: *14 inch display 1080p cool for a bit of work on the road or coffee shop or whatever. * <27 inch 4k screen, same it's OK for gaming or if you upscale fonts, but otherwise will strain the eyes for day to day work. I highly recommend NOT to use such setup in native size to spend hours each days of programming or coding work (or anything text based) with such configuration. * >32 inch 4k, optimally >38/39 inch, fine, though if sitting too close also not too cool as you would have to move your head a lot when reading a lot or typing. But perfectly fine * my ideal setup for someone who does a lot of text based work: a 27-30 or so inch screen, 16:10 not 16:9 in WQXGA 2560x1600 resolution.
I think what the other user was saying, if it does not show up in device manager even as unrecognized then you have a defective device at hand or have not turned on hardware channels to detect such device. And I agree with that, it's not driver related at this point. Maybe the card is broken or to just give you an example, some x16 slots are not activated in dual cpu Mainboards unless you do use 2 cpus. Inserting only 1 will only activate the pcie lanes serviced by that one cpu but not the others (should not say "serviced" but I guess you get the point) . In this case inserting a video card into such non serviced slot will not work.
most desk have a depth of 30 inches, your viewing your monitor approximately 18 inches away sitting normally. Head movement is natural when your viewing more than 1 screen at 1080p. Unless you're a frog who can move each eye independently, that would be really weird...
You can really even put something old like I don't know, for example close to 10 years old Radeon 69xx series, I have mine for around that time and I do have 2 DVI and 4 display ports on it for 6 monitor setup even, how does that sounds ?