A couple years ago I built a new Ryzen system. I wanted to go all-out on the hardware as much as possible, and so I cut a few corners to save money. I recycled my old case, and power supply, and I reused my R9 290x until I could save money to buy a 1080ti. At the time the prevailing wisdom was "there is no reason to buy AMD graphics". Pretty much every tech website, and every tech reviewer on Youtube said the same thing, AMD lost the graphics war, Nvidia was better in every metric. Nvidia was better for performance, better price, better technology, faster, more powerful, in fact some went so far as to accuse AMD of scamming their customers (blaming AMD for the mining boom, and by extension the high prices). So when my R9 290x unexpectedly died and I need to get a new GPU right away, still unable to afford a 1080ti, I bought what was, by common knowledge at the time, the best GPU for under $300, a GTX 1060 6gb.
When I plugged in the 1060 and fired up GTA V, I was immediately shocked. Not shocked by how amazing it was. Not shocked by the triple-digit FPS. Not shocked by the amazing RGB lighting. Not even shocked from forgetting my wrist strap and touching the PSU while wearing fluffy socks. I was shocked by how UGLY the game was. I immediately went into settings and made sure everythign was set to high/max. It was, but it was ugly. I went to my garage to check out my cars, they all looked so dull. I got in a car and started driving around at high speeds to test the frame rate. The FPS was great, easily stable at over 90-115. Performance was probably 10-15% better than my R9 290x, but my god it was ugly. The colors were dull, the contrast was non-existant. Black was grey and white was light grey. Matter of fact, blue was grey, red was grey, yellow was grey, and green was grey too. Chrome looked like steel, steel looked like dull grey plastic.
After a while, I convinced myself I'm just a AMD fanboy and I'm imagining things. But after some time went by, I decided to rebuild my old PC for the living room, and I wanted the same graphics card I had before. Well I sent it to Asus for repair, and they quoted me a price of $875. LOL So I went on Ebay and got a RX 580 instead. It's not exactly the same, but close enough, a bit of an upgrade but similar enough architecture and software so it will still feel like the same system.
Well, I put the RX 580 in my old PC, and it looks better than my new PC. Now I can no longer ignore this.
I tested some other games, and this is not the case for all games. Most games seem to show slightly better visuals on the RX 580, some look exactly the same on both cards, none look better on Nvidia. Keep in mind I tested all games with the exact same settings. But GTA V was by far the most obvious.
Here is a video I record of GTA V on the GTX 1060 vs the RX 580 with the same settings (mostly high/ultra, MSAA off). I would be very interested to hear anyone's opinions on this. What is causing it for example. My pet theory is that Nvidia are intentionally down-scaling their textures and compressing their color spectrum in order to reduce GPU processing requirements and boost their FPS performance. But that's just my theory.
I made a video showing the difference in GTA V. Keep in mind it's not this obvious in most games. For example in Rise of The Tomb Raider it seems to but just a small difference in fog/smoke quality and slightly reduced non-player textures, you might not even notice. In GTA the difference cannot be ignored.