I'm not sure if I'm asking this right but i'll give it a shot.
I have recently bought a Radeon HD 7750, the reason i bought this is because my computer has a crappy integrated HD 2000 and a 300w psu.
I have researched enough to figure out that the 7750 runs great on a 300w psu because it doesn't need any connection to the PSU it only plug into the motherboard.
But my question is; how does the 7750 get its power than? Obviously from the motherboard, but does this now mean my motherboard is going to be consuming more power from the PSU, or does the motherboard still run on the same amount of power?
Sorry if this is confusing to read, but I'm a learning computer user and have just been really confused on this subject.
Thank you for the quick reply, and sorry for my lack of knowledge but isn't the PCIe slot on the motherboard? Basically, if a card can run off of solely the PCIe slot, does this mean that the PCIe slot was made specifically so that it cant go over the max power consumption?