6 Video cards at once?

[Team kizb]

I'm working on putting together a SETI@Home rig and want to run 6 8800 GTs on one motherboard. So far the GIGABYTE GA-990FXA-UD7 is the only motherboard that might work. There website says it has 2 slots that run at x16, 2 that run at x8 and 2 that run at x4 with support of Quad SLI, but I can't seem to find if you can really use all 6 PCIe slots at once.

So does anyone know if the GIGABYTE GA-990FXA-UD7 could run 6 8800 GTs at once?

[petteyg359]

Check the manual to make sure it doesn't disable any slots when you've filled the first four, but it probably is fine. SLI is unimportant. You're probably going to be running a separate client for each card, anyway.

EDIT: Gigabyte's page says populating all four upper slots will make them operate at x8 each, but it doesn't say it disables the x4 slots. Should be fine.

[4GHZ_or_bust]

I don't have the number at hand but wouldn't a single GTX 580 perform better than 6 8800 GT in term of folding power? a single 580 would draw a lot less power than 6 8800s. From a quick Google search, 12v 24A per video card is required and that is over 1700w total just for 6 video cards. :o :o :o Add in oh about 300w minimum for the mobo and CPU.

In USA, many household AC outlet are rated max 15A or 1650w. You'd need to use a 20A outlet if you have one, 20A outlet in USA has one slot that looks like a sideway "T" pictured below. 25A outlet exists in USA but are rare and has 2 sideway "T"s

Or use a 220v outlet normally reserved for electric appliances like stove, dryer, water heater, etc. assuming the PSU you are getting has 220v support.

[Team kizb]

I don't have the number at hand but wouldn't a single GTX 580 perform better than 6 8800 GT in term of folding power? a single 580 would draw a lot less power than 6 8800s. From a quick Google search, 12v 24A per video card is required and that is over 1700w total just for 6 video cards. :o :o :o Add in oh about 300w minimum for the mobo and CPU.

In USA, many household AC outlet are rated max 15A or 1650w. You'd need to use a 20A outlet if you have one, 20A outlet in USA has one slot that looks like a sideway "T" pictured below. 25A outlet exists in USA but are rare and has 2 sideway "T"s

Or use a 220v outlet normally reserved for electric appliances like stove, dryer, water heater, etc. assuming the PSU you are getting has 220v support.

Here in Germany I get 220v from outlets :D

I've been doing lots of reading and I think I'm going to try 3 GTX 295's instead. I already have most of the parts, or they are on the way. Here is the setup, please let me know if anyone sees any issues I may have with these components.

EVGA nForce 780i SLI Motherboard (132-CK-NF78-A1)
Intel Core 2 Quad Q9550 2.83 GHz
Coolermaster Hyper 212 Plus
G.SKILL 4GB (2 x 2GB) DDR2 800 (PC2 6400)
3x EVGA GeForce GTX 295's
ENERMAX MAXREVO EMR1350EWT 1350W PSU
CM HAF 912 plus (1 front 200m, 1 top 200m, 1 side 140m, 1 rear 120mm)

[eaglescouter]

Since you are building this crunching box and do not already have the video cards on hand I would suggest you spend your video card money on fewer high end cards. Especially when you consider the number of CPU cores that need to be dedicated to feeding the GPU, thus the CPU cores are no longer crunching on those cores.

What is your video budget for this build?

[Team kizb]

Since you are building this crunching box and do not already have the video cards on hand I would suggest you spend your video card money on fewer high end cards. Especially when you consider the number of CPU cores that need to be dedicated to feeding the GPU, thus the CPU cores are no longer crunching on those cores.

What is your video budget for this build?

I have a few video cards already, thinking now maybe 6 8800 GT's might not be the best direction to go. Here is what I have on hand:

3 8800 GT's
2 GTX 295's
2 GTX 470's

[Team kizb]

Since I already have 3 8800 GTs I'm going to put them in a rig with an E8400 and see how it does. That will free up my Q9550 to run 3 295s.