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Topic: Four 58xx GPUs on an older AMD Motherboard? (Read 1238 times)

legendary
Activity: 1344
Merit: 1004
August 10, 2012, 06:22:07 AM
#3
Wish there was an accurate way of measuring power draw on the PCI-E slot. I honestly don't think it's very much. If anything, it powers the fan and probably some of the basic IC's. The PCI-E power plugs powers the GPU itself.

Also *shrug* I use unpowered risers on my 4x 5970 rig as well as on my lesser rigs. I've never had a problem. The worst thing I did was melt a molex cable because I powered 2 5850's at stock volts through a single molex line (melted the modular power plug on the power supply. The power supply still works Grin). The motherboard is also 100% unharmed and fully functional.

You MAY need to short pci-e presence pins. It's hit and miss if a motherboard needs this, but it always works unless the manufacturer explicitly states that certain slots are turned off when others are populated, such as my MSI Z77A-G45 (7 PCI-E slots. PCIE_3 turns off when PCIE_4 is populated)
sr. member
Activity: 280
Merit: 250
Sometimes man, just sometimes.....
I wouldnt worry about that, remember, most of the power is going to be drawn through the PSU and the connectors there.  I have an old, refurb Asus 85N SLI board with a 5870 and a 5830 running on it OC and it runs just fine.  There is a reason why you can run them through the PCIEx1 slots, not much going through the bus.  Just make sure you have a PSU that can handle that much power draw over the 12v rail and you should be good to go.
member
Activity: 113
Merit: 10
So I've got an AM2+ mobo that has a single pcie 16x and three 1x pcie slots. Here is a pic of my board. http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01635688

I currently have a gpu in the 16x slot, but I am hoping to move it to an open-style case, upgrade the power supply, and use extender ribbons to see if I can get 4 GPUs running in there at once (5850s or 5870s).

Trouble is, I'm afraid of overloading the board and causing terrible tragedy. Does anyone have experience doing this kind of setup with an older board or any advice on how to avoid catastrophy?

I was thinking of looking at those powered 1x -> 16x adapters to help relieve some of the strain on the slot power...
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