Yes, the motherboard supplies power to the CPU through its power delivery system.
Yes, the motherboard supplies power to the CPU through its power delivery system.
According to my understanding, the 24-pin ATX port doesn’t supply power to the CPU, or very little if any. It features just two +12V connections, whereas an 8-pin EPS port has four of those. The 8-pin EPS units can handle up to 384W, while the 4-pin EPS models support about 150W.
It likely hinges on the motherboard's layout. Apart from the minimal power systems built to operate without a traditional CPU power cable (like soldered low-power CPUs), I’d lean toward the 24-pin connector rarely touching the CPU power supply. The power header must exist, and it provides sufficient capacity for engineers to avoid complex routing.