5 GPU 280x rig - What am I missing?

[23940103]

what am i missing?

GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard
AMD Sempron 145 Processor
(2) Corsair RM Series 850 Watt ATX/EPS 80PLUS Gold-Certified Power Supply - CP-9020056-NA RM850
P3 International P4400 Kill A Watt Electricity Usage Monitor
Kingston Technology HyperX 8 GB (2x4 GB Modules) 1600 MHz DDR3 Dual Channel Kit (PC3 12800) 240-Pin SDRAM KHX1600C9D3K2/8GX

using crates


(2) Powercolor Radeon R9 280X OC 1030MHZ 3GB 6.0GBPS GDDR5 DVI HDMI 2XMINIDP PCI-E Video Card
(1) Asus MATRIX-R9280X-P-3GD5 Radeon R9 280X DDR5 3GB256-bit PCIE 3.0 DVI/DP/HDMI
(1) GIGABYTE Radeon R9 280x OC GV-R928XOC-3GD REV2
(1) XFX R9-280X-TDBD AMD Radeon R9 280X 3GB GDDR5 2DVI/HDMI/2Mini DisplayPort PCI-Express Video Card


I'm confused on the risers
Expansion Slots: 2 x PCI Express x16 slot running at x16 ,1x PCI Express x4 slots, 2 x PCI Express x1 slot, 1x PCI slots

do i need (5) 16x1 risers or
(2) 16x16, (1) 16x4, and (2) 16x1


Im planning on running ubuntu on a memory stick since i read that's the best way to go!

[23940103]

looking to get a 8gb memory stick

[ineedit]

what am i missing?

GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard
AMD Sempron 145 Processor
(2) Corsair RM Series 850 Watt ATX/EPS 80PLUS Gold-Certified Power Supply - CP-9020056-NA RM850
P3 International P4400 Kill A Watt Electricity Usage Monitor
Kingston Technology HyperX 8 GB (2x4 GB Modules) 1600 MHz DDR3 Dual Channel Kit (PC3 12800) 240-Pin SDRAM KHX1600C9D3K2/8GX

using crates


(2) Powercolor Radeon R9 280X OC 1030MHZ 3GB 6.0GBPS GDDR5 DVI HDMI 2XMINIDP PCI-E Video Card
(1) Asus MATRIX-R9280X-P-3GD5 Radeon R9 280X DDR5 3GB256-bit PCIE 3.0 DVI/DP/HDMI
(1) GIGABYTE Radeon R9 280x OC GV-R928XOC-3GD REV2
(1) XFX R9-280X-TDBD AMD Radeon R9 280X 3GB GDDR5 2DVI/HDMI/2Mini DisplayPort PCI-Express Video Card


I'm confused on the risers
Expansion Slots: 2 x PCI Express x16 slot running at x16 ,1x PCI Express x4 slots, 2 x PCI Express x1 slot, 1x PCI slots

do i need (5) 16x1 risers or
(2) 16x16, (1) 16x4, and (2) 16x1


Im planning on running ubuntu on a memory stick since i read that's the best way to go!

You could do it with either (2) 16x16, (1) 16x4, and (2) 16x1 powered risers or (1) 16x16 and (4) 16x1 powered risers. Most OS drivers get a bit uppity if the primary video card is not x16.

[23940103]

i heard it's best to try to avoid power risers...

[CounterStrike]

i heard it's best to try to avoid power risers...

Wrong, you will need power risers if you have more then 2-3 GPU cause it would put too much weight on your motherboard power...

[crazyates]

You want powered risers, absolutely. 5 GPUs all pulling 25+W from your motherboard, and it will be toast.

As for the actual number of risers, you can use whatever physically fits. If you want to use 16x -> 16x risers in the 16x slots, you can. You can also use 1x -> 16x risers in ALL slots, and they'll still work. I use those 1x -> 16x USB risers on our 5x GPU rigs, and they work great. Highly recommend them, as the added flexibility of a USB cable gives you a lot more freedom to reposition your GPUs in ways you couldn't before, with no worries of damaging or breaking the connections.

[23940103]

ok i ordered (5) 16x1 power risers

probably just hook up 2 gpus directly to mobo and 3 on power risers