
Originally Posted by
prof818
No, thats not what i mean.
Most power supplies are constructed with multiple 5V and 12V rails. Each of these rails is only capable of giving out a certain amount of power.
So for instance, the PSU might be capable of 420W, but you can only pull 100 from each 12V rail, with the remainder being split among the 5V rails.
So, if the graphics card + hard drives and half the motherboard are being run on one rail, with only the motherboard on the other, the voltage would dip on the over loaded rail.