If I bought a 5800k and disabled the Gpu would the 100 watt rating drop down to.. lets say 75 watts?
The wattage should go down but I don't know by how much. Its wattage is pretty low anyways, a typical system power draw for a 5800K build under heavy load (with no dedicated GPU) is like <130W.
If you don't want the iGPU there at all, that is literally an Athlon X4 750k, which is still listed as a 100W part.
But that's TDP, which is not the same as power usage. It's at best an upper limit on power usage.
For example, the Titan, 780, and 780ti all have the same listed TDP, but the 780ti actually pulls ~10% more power than a Titan.
So it's difficult to say how much, but yes, the power usage would go down.
Yeah I was looking at the athlons but I just found a 6600K with a good combo So I thought why not take the extra frequency boost unless it uses a considerable amount of more power. it also comes with 2 free games.