Hi guys, same shitty problem here, I'll tell you how started for me and my experience. (gosh this is starting to seem like a therapy group xD).
well all started when I bought the RX 480, I started to see weird things like a squared pattern (Shadow acne) in some places on games, I had a GTX 650 before and I didn't notice that kind of things, or I just was looking at the FPS counter more than how actually the game looked like. I tried putting my RX 480 on a friend's PC, the same, and when she put her graphics card back, guess what, the same fucking problem.
I thought it was just a driver issue cause she had another 480 so I contacted with the AMD technical support and they thought the graphics card was defective. I changed back to the GTX 650 doing a clean installation of the drivers with the DDU software, same shit,
I knew it wasn't normal so I sent back the graphics card and the motherboard to the store. They replaced the mother board but couldn't replace the graphics card cause it was discontinued so they refund the money and I bought a GTX 1060, again this shit:
It might look different to other people, shadow acne looks different on other games, depends on how the games are coded or optimized.
I was so upset, so I sent back again all the hardware but the hard drives so they could fix it. They replaced the graphics card again and they told me everything worked correctly. I haven't assemble the PC yet cause scares the shit out of me, if that happens again I'd be so done.
So I've been thinking, whether is a software problem, then formatting the hard drives or getting a new ones and reinstalling windows should fix it (I'm pretty sure a lot of us have tried that without result), or is external to the PC, I don't think any peripherals like mice or keyboards could cause this problem, it'd be silly, so I think it could be the electrical installation of the house or maybe the monitor which is conected directly to the graphics card, besides I noticed that even playing at 60 FPS or above with Vsync enabled it doesn't feel smooth at all in some games, I know it would be weird too, but those two things are the constants when we conect the PC for the first time. it just doesn't make sense to be a software or hardware problem for those people who have bought a completely new PC.
I might have written a lot of bullshit here, but i'm just trying to help find the cause and hopefully together find the solution some day.