Hi there,
The length was due to both show source material as well as the intricacies on the PC we are delving deep in the Tech side of things. Console is very easy, as you know, just flip the switch and it just plays as the programming is adverted to do. With the myriad of the PC side options, you have ALOT of work to get into to achieve specific goals and directions; at a serious cost, that consoles can't compare.
That said, yes depending on the GTX 1080 you get and then know the proper connectors for it. It is very BAD option to use any '6pin>8PIN' conversions, as noted in many threads "things happen", and it best to have a 'pure' connection (a 6pin for a 6 Pin or 8 pin for a 8pin). I can attest my own situation I too found out the hardware, and yes a new PSU with proper cabled connections was required to alleviate all my issues.
So in summary, you can get a 1080, but you need at least 600W pumping out (which you don't) and have the proper 'pure' connections to power the 1080. With that you will constantly overbeef the graphics (all games on Ultra) with 60FPS or better on a 1080P display. If you push to 4K, you need to get the 'mods' (if any) or alternative version of the game 'graphics mode' that will use 4K textures and ULTRA POLY models that will make it look as shown in the GTA V mod as compared to the 'normal' textures and poly models you will see on the advertized video game play. You won't "see" that 4K detail, but will just be 'stretching' things into a 4K SIZE display
http://blog.artbeats.com/blog/wp-content/uploads/2013/10/Size-Comparison-Overlay-630.jpg .
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ADDITIONAL DETAIL to assist and clarifying some important parts.
There is more to the issue than "the closer to 4K resolution, the better" and that is why I brought up FPS. We aren't talking "playing at 40FPS is unplayable" elitism, what
we are talking about is single to 10s FPS or worse (as mentioned) tearing, skipping, 'teleporting', lags, etc. "in the game" due to the difference between what is being SENT to display and what IS displayed.
I am not sure how much you know (coming from console perspective) about the difference on PC, which most people in the PC community really don't get either, about "FPS" and "Hz". The FPS counters displayed is about what the CPU and GPU are rendering to 'send' to a display. The Hz is the actual number of frames displayed on the screen you actually see, no matter what was SENT to it. So for your "30FPS" for example, the monitor would then take time to actually calculate and "add" duplicate frames of the 30 it got and then fill in for the actual 60Hz it displays (60 Frames per second of display). Conversely if you were sending 120FPS it would 'drop' every other frame (skipping across screen) or drop HALF (sudden teleport) the frames to make it 'fit' on the 60Hz. Add in the variable 43, 89FPs and so on, and you can see how messy this gets, and in turn affects your game play.
So the remedy has been to get the GPU pumping enough (60FPS) all the time (even if you had 20 helicopters firing 20 Rockets each all at the same time exploding on the screen) so there wouldn't be that much of an issue. Because they got very good at pumping out that much power and could achieve now 100+ FPS if they wanted to the display (100, 120, 144Hz) got bumped up so that 'action' (running, flying, moving in anyway) seemed realistic and "fluid".
Now with the move to 2K, 4K and then 8K displays (larger size AND much more detail aka pixels to 'fill' in) and, this impacts all those "gains" they just made. It isn't (as I mentioned) just getting a "HIGH" FPS, but to match the HZ consistently so you don't get bad performance in the game itself, and having a larger SIZE screen as well a MUCH more detail to also 'fill in' is a ton more data to render.
4K does require higher poly model rendering. For example look closely at the ears and nose in comparison, to achieve the smoother realistic not jaggy parts requires alot more rendering by the GPU and CPU just one that ONE head, and now multiply that times the number of 'people' on the screen and add in the eyes, the hands, the body, clothing, buildings, etc. etc. etc. all in one simple second on the screen.
https://tplinnovator.files.wordpress.com/2015/09/female_head_bases___low__mid_n_high_poly_by_lbg44-d4l3ecx.jpg
4K does require 4K rendered textures, as shown in the previous GTA V 4K mod above, as compared to what you see if you review the normal GTA V Video Game Trailer, you see a TON of difference on how 'detailed' the water is, the paint on the car is, how the Sun looks, etc. etc. etc. What been happening though is upscaling as I mentioned, where your making a 4K SIZE screen, but your using lower end poly models and textures to 'stretch' to fit that screen.
This is what people 'want' when they say 4K
https://s3.amazonaws.com/red_3/uploads/asset_image/image/519a4b3aa48c373941000957/scaling3.jpg
This is what they get when they can't afford the investment (as we both mentioned) when they play
https://s3.amazonaws.com/red_3/uploads/asset_image/image/5196af342f74a94eef001224/scaling2.jpg
AND the game has lag, low FPS, "issues" etc. when your playing.
So right now, if you wish to play 1080P 60Hz / 60 FPS on a SINGLE screen PC, that is what the GAMES are set for and the hardware is tuned for. If you wish to push PAST those, then you need to modify some other parts lower (less FPS, garbage looking graphics, etc.) to compensate if your not willing to pay for the hardware costs to make that standard FIT into the goal (4K, Multiple screens, 240HZ screens, 200FPS, etc.).