Quote from: AlliumPorrum on December 21, 2013, 09:33:07 PM

Everywhere it is said that you MUST have a powered risers if you are going to use more than 3 GPUs per mining rig. Now that I got my Asus R9 290's, I noticed that there is a separate PCIe power input in them.

So I'm just wondering; what exactly is the purpose for the powered riser, vs. one without a power? Are powered ones needed only with some older GPUS's without a dedicated power input? Do ALL R9 cards (270,280,290) a PCIe power input, so there wouldn't be a need for a powered version of the riser at all?

This was the first search result for "powered risers", but it hasn't been answered? I too would like to explain the differences between powered and unpowered risers.