Planning to buy a graphic card looking at 6950 XT or Nvidia 3090 Ti. I have AMD Process "AMD Ryzen 7 2700X Eight-Core Processor, 4150 Mhz, 8 Core(s), 16 Logical Processor(s)" someone told me that AMD graphic card work better with AMD processor should i get 6950XT anyone now is that a case ?
What handles the GPU's task is the OS using drivers and abstraction model. There some times synergy between certain GPU's and CPU's (Mainly related to the PCI-E lanes).
Also you can find combinations which work better, but it usually has nothing to do with the fast the GPU and CPU are made by the same company.
Personally, unless you have something with CUDA, I'd go with AMD.