Which video card is better to choose for mat. PCIe 2.0 x16 boards: PCIe 3.0 x8 or PCIe 3.0 x16?

Question

Video cards

There is a motherboard with PCIe 2.0 x16 and it has two graphics cards: 1) PCIe 3.0 x8 (maximum memory bandwidth 112 GB / s) and 2) PCIe 3.0 x16 (maximum memory bandwidth 96 GB / s). But, since the PCIe versions on the mat. board and video cards are different, then the video cards will work in PCIe 2.0 x8 and PCIe 2.0 x16 modes (if I understand this correctly). And since PCIe 2.0 x16 has more bandwidth than PCIe 2.0 x8, it is more profitable to install a second video card (PCIe 3.0 x16 with a memory bandwidth of 96 GB / s). Correctly?

Answer 1

As I understand it, they were going to install nothing more than rtx 3090 for games in 8K, since such a question arose.
Considering that the mother with 2.0 was most likely taken for 200r on Avito, then the vidyakha will be from the same category, in this case it is generally pointless to think about the bus speed between the vidyakha and the motherboard, you won’t notice the difference at all

Answer 2

The dependence of the performance of the same video card on the bus will be almost at the level of error.
There have already been such questions and tests: https://www.youtube.com/watch?v=UQ0_G9W4b_M
Pay attention to the end of the video, when the tire was artificially slaughtered. Even so, the difference is not catastrophic. So choose according to the performance of the video card itself and don't bother about the bus.