Yes, it is feasible to connect a CPU to a motherboard using a PCI Express bus.
Yes, it is feasible to connect a CPU to a motherboard using a PCI Express bus.
They don't develop such cards because integrating multiple CPU sockets would require custom enclosures with built-in cooling systems. Users would need to remove the cooler to install CPUs and then reinstall it, similar to swapping GPU coolers. This approach would simplify manufacturing by allowing a single enclosure to house four CPUs, each with four sockets across four PCIe slots. It could make building a system with 16 CPUs more straightforward. Think about having 17 Threadrippers, each packed with over 1,100 cores.
Does the system use the same RAM as the rest? If a GPU can access system RAM, why can't other things on the card work? I also think the workload distribution would be similar to dual socket motherboards.
It works somewhat but mainly not. You can include co-processors, which are essentially GPUs that run CPU commands instead of GPU ones, but the PCIe connection isn't powerful enough for a full CPU to operate efficiently through it. Also, one of the biggest advantages of a CPU is its extremely quick access to a vast memory space, something a PCIe card can't match.
Your GPU isn't sharing system RAM. Using system memory as VRAM will significantly boost performance since it's much faster than the card's RAM.
You'd need significantly higher speeds than PCIe 3.0 to match its performance.
You could mount the RAM directly onto the card and make it upgradeable by aligning each slot neatly with the back of the board. It would feature four RAM slots—two for board connections and two for upward orientation. The idea of achieving 20 times the bandwidth is intriguing; it makes me think about integrating a GPU into a CPU-like socket.