CPU is talked by 3 phase or 4 phase, why GPU isn't?

When it comes to CPU of motherboard, we often hear 3 phases or 4 phases;
but why GPU of graphic card didn't hear such terms?

Core?????

If you're talking about power delivery, then the answer is that GPUs do not come in separate parts (not counting heatsink's) - that is, you don't buy a card and a gpu core and put them together, you just buy the whole package. With CPUs and motherboards, the motherboards are designed to handle a variety of CPUs, some of which may need 3 phase power designs and others which may need more phases (bit of a simplification, actually). In the case of GPUs, the card is designed to handle the GPU core placed upon it during manufacturing. There is no need to concern yourself with any specifications regarding the power of your video card other than how much wattage your power supply will need, though you will want to make sure that the motherboard you wish to buy will be able to run the CPU you wish to put in it at the speed you want to run it at (presumably if the MB says it supports the CPU, it will handle the CPU at stock speeds; overclocking increases power requirements, however, and may alter things).