PCI-E Risers

[cbrunny]

Specifically for a gaming setup with no mining whatsoever, would a pci-e riser need to be powered or will unpowered work equally well? The cards are 7970s, which have power inputs direct from the PSU, but I thought they also draw from pci-e slot as well.

Side-question, if all a riser does is create an extension for a pci-e slot, why would the power from the pci-e slot not be extended as the data transfer is?

 

[Attic]

Specifically for a gaming setup with no mining whatsoever, would a pci-e riser need to be powered or will unpowered work equally well? The cards are 7970s, which have power inputs direct from the PSU, but I thought they also draw from pci-e slot as well.

Side-question, if all a riser does is create an extension for a pci-e slot, why would the power from the pci-e slot not be extended as the data transfer is?

Powered risers are only neccessary for 3 or more cards off one motherboard. This is so the motherboard doesn't get overloaded.

For 2, and even 3 card gaming setups non powered risers would be fine. The power from the slot is extended in a non powered riser. If you had 6 cards all drawing 75w's from PCI E slots it would a problem, which is why powered risers were used at 3 or more cards in mining setups.

 

[cbrunny]

Ah, so because I`m not drawing a constant 75w from the slot, it isn`t an issue.. interesting.

FWIW, I am running 3 cards off one board, all 7970s.

 

[Attic]

Ah, so because I`m not drawing a constant 75w from the slot, it isn`t an issue.. interesting.

FWIW, I am running 3 cards off one board, all 7970s.

Powered risers were mostly needed for running graphics cards off of 1x PCI express slots which are built to deliver 25w, where a graphics card is built to take 75w from the motherboard slot. The powered risers allowed the 1x slots to be used with full length video cards and get fed 75 direct from PSU instead of through the motherboard.

Which mainboard?
If your board is made with 3x PCI express x16 slots you will most likely be fine with unpowered risers. If you want to take some stress of the motherboard you could use 16x-16x powered risers, but main thing is to make sure you get the 16x to 16x risers.

 

[cbrunny]

I`m using ASUS Sabertooth 990fx R2.0. I`ve already ordered the 16x to 16x unpowered riser so hopefully it works! Thanks for your help.