Now the system has an nVidia 3070. The system runs on a triple screen, each full HD screen. I want to upgrade my video card, which one is better to upgrade to: 4070 or 7800xt?
Well with everything else being quite equal between those two cards, Nvidia is usually the choice for sim racing. I use an AMD card myself and while everything works, the performance in certain titles like iRacing is lower with AMD relatively speaking compared to mainstream games. The flip side is that 7800XT has 4 GB more VRAM and VRAM as we know is used quite a lot by some modern games.
I'm in a similar boat, I was reading about it and it seems a lot of people have issues with AMD drivers. I remember the last time I had one(may have still been called ATI back then), it also had a lot of driver issues.
First question is do you play other game genres or is your main focus sim racing titles? The 4070, especially the 4070 Super, is a really great card for both gaming and non-gaming applications (e.g. Lumion rendering). The 7800XT is an excellent pick if your gaming across gaming genres and if ray tracing isn't of interest. The Radeon GPU will likely be faster than the 4070 in most games - the 4070 Super will have closed this gap. The drivers from Nvidia have been lots of misses and a few good ones since the 40 series launched. The Nvidia Reddit thread is a good source of user feedback and often has driver vs driver benchmarks. The latest gaming and studio drivers appear to have fixed issues with some users waiting 12 months for fixes e.g. graphical artifacts when using Chrome and Edge browsers. From what I've read online, AMD have been doing a better job. 45 game bench review 4070 vs 7800XT: https://www.techspot.com/review/2736-geforce-rtx-4070-vs-radeon-7800-xt/ 4070 Super vs 7800XT: Video discussing 'best' GPU at each price point:
AMD still (I believe) cheats with transparency, so instead of proper transparency you get dithering (dots) in trees etc. In rF2 the HUD fonts can suffer as well. It's a minor gripe, but if you notice it and it bothers you, it never goes away.
As I said, if you notice it, and it bothers you. I should say this affects all games, including ones where there is more frequent interaction with foliage.