5 ati 280x on one mother board. Multiple PSUs safe?

[joneustace]

I'm looking to power 5 gigabyte 280x on one system. I've heard that the peak wattage the cards will take is 400 watts each, but seen elsewhere that it's 300 watts each. Either way, I need to have multiple PSUs to make this system work, I cannot find a single PSU that will power my hardware.

I've found an adapter : here that connects to PSUs.

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background.

 

[scoobydenon]

Why would you want 5 280"s on one system?

 

[joneustace]

Why would you want 5 280"s on one system?

Mining.

 

[unknownofprob]

I'm looking to power 5 gigabyte 280x on one system. I've heard that the peak wattage the cards will take is 400 watts each, but seen elsewhere that it's 300 watts each. Either way, I need to have multiple PSUs to make this system work, I cannot find a single PSU that will power my hardware.

I've found an adapter : here that connects to PSUs.

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background.

Tri-fire is enough of a problem but 5-cards in crossfire.....bad bad idea and I don't even think you can go further then quad-fire so you probably can't even do that anyways.The 280x is a 250 watt card not 400 or 300 just 250 as it's just basically a 7970 GHz just re-branded. Multiple PSU is fine but game support and anything with 5 cards will be a nightmare, I'd just get two R9 290's or 2 GTX 780/Ti's for a good price and will perform better as micro-stutter and support will be terrible with 5 AMD cards.

 

[joneustace]

I'm looking to power 5 gigabyte 280x on one system. I've heard that the peak wattage the cards will take is 400 watts each, but seen elsewhere that it's 300 watts each. Either way, I need to have multiple PSUs to make this system work, I cannot find a single PSU that will power my hardware.

I've found an adapter : here that connects to PSUs.

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background.

Tri-fire is enough of a problem but 5-cards in crossfire.....bad bad idea and I don't even think you can go further then quad-fire so you probably can't even do that anyways.The 280x is a 250 watt card not 400 or 300 just 250 as it's just basically a 7970 GHz just re-branded. Multiple PSU is fine but game support and anything with 5 cards will be a nightmare, I'd just get two R9 290's or 2 GTX 780/Ti's for a good price and will perform better as micro-stutter and support will be terrible with 5 AMD cards.

I'm not looking to crossfire. I'm using the cards for mining. Each card would be running individually.

 

[giantbucket]

Has your semi-electrical background bothered to do some basic math, such as 5 cards @ 400W each plus approx 125W for CPU = 2150W which means you need to install a dedicated 20A circuit for this?

Even at 300W each you're on a 20A circuit simply due to PSU efficiency

 

[rolli59]

Mining!
In use each cards consume around 250watts around 350watts stress test http://www.techpowerup.com/reviews/Gigabyte/R9_280X_OC/24.html
Using multiple PSU's works if you jump the 24 pin ATX connector.

 

[joneustace]

Has your semi-electrical background bothered to do some basic math, such as 5 cards @ 400W each plus approx 125W for CPU = 2150W which means you need to install a dedicated 20A circuit for this?

Even at 300W each you're on a 20A circuit simply due to PSU efficiency

Yes my semi-electrical background has bothered to do some math. It's called two receptacles on different circuits.

 

[joneustace]

Mining!
In use each cards consume around 250watts around 350watts stress test http://www.techpowerup.com/reviews/Gigabyte/R9_280X_OC/24.html
Using multiple PSU's works if you jump the 24 pin ATX connector.

Yes I know that this will work... but do I risk the possibility of frying my system somehow? I've heard multiple PSUs isn't a good idea, what am I missing here? I don't see what the risk is.

 

[aevm]

Has your semi-electrical background bothered to do some basic math, such as 5 cards @ 400W each plus approx 125W for CPU = 2150W which means you need to install a dedicated 20A circuit for this?

Even at 300W each you're on a 20A circuit simply due to PSU efficiency

It may be cheaper and simpler to build two PCs, with 2 or 3 cards each, and plug them in different circuits.

 

[unknownofprob]

I'd go for 4 R9 290's and get a 1500 Watt PSU to get rid of the dual PSU problem. 4 R9 290's will perform pretty similar if not better then 5 R9 280x's. Each R9 290 draws 300 watts so having a one might PSU is best.

 

[joneustace]

I'd go for 4 R9 290's and get a 1500 Watt PSU to get rid of the dual PSU problem. 4 R9 290's will perform pretty similar if not better then 5 R9 280x's. Each R9 290 draws 300 watts so having a one might PSU is best.

Problem is, 1500w PSUs are impossible to come by ATM, unless you're willing to wait. I want to know if multiple PSUs is safe with an adapter. If it isn't safe I want to know why.

 

[Neverrazor]

joneustace said:
I'm looking to power 5 gigabyte 280x on one system. I've heard that the peak wattage the cards will take is 400 watts each, but seen elsewhere that it's 300 watts each. Either way, I need to have multiple PSUs to make this system work, I cannot find a single PSU that will power my hardware.

I've found an adapter : here that connects to PSUs.

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background.


Tri-fire is enough of a problem but 5-cards in crossfire.....bad bad idea and I don't even think you can go further then quad-fire so you probably can't even do that anyways.The 280x is a 250 watt card not 400 or 300 just 250 as it's just basically a 7970 GHz just re-branded. Multiple PSU is fine but game support and anything with 5 cards will be a nightmare, I'd just get two R9 290's or 2 GTX 780/Ti's for a good price and will perform better as micro-stutter and support will be terrible with 5 AMD cards. ....




.... can't u just read .... he said MINING !

this board http://www.newegg.com/Product/Product.aspx?Item=N82E16813157366
Look u can mount up to 7 cards .. but you need risers so u can use the psi 1 to the 16x ...
you can find here http://www.gobitgo.com/articles/1001/How-To-Correctly-Use-and-Install-PCI-E-Riser-Cables/


maybe you will need 2 psu for the 5x 280x .... yeah... 250x5 = 1250 .. i would suggest getting 2x 700W psu .. caz u need power for yourboard and cpu as well...

Get a decent Fan that goes up all those cards caz that will generate a huge amount of heat ...

 

[giantbucket]

Separate circuits might cause ground loop issues - and if a fuse/breaker blows on one line it might be bad for the system. Better off getting a 20A circuit or using the stove outlet.

Other than that, no major issues running dual PSU to a single outlet.

 

[unknownofprob]

joneustace said:
I'm looking to power 5 gigabyte 280x on one system. I've heard that the peak wattage the cards will take is 400 watts each, but seen elsewhere that it's 300 watts each. Either way, I need to have multiple PSUs to make this system work, I cannot find a single PSU that will power my hardware.

I've found an adapter : here that connects to PSUs.

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background.


Tri-fire is enough of a problem but 5-cards in crossfire.....bad bad idea and I don't even think you can go further then quad-fire so you probably can't even do that anyways.The 280x is a 250 watt card not 400 or 300 just 250 as it's just basically a 7970 GHz just re-branded. Multiple PSU is fine but game support and anything with 5 cards will be a nightmare, I'd just get two R9 290's or 2 GTX 780/Ti's for a good price and will perform better as micro-stutter and support will be terrible with 5 AMD cards. ....




.... can't u just read .... he said MINING !

this board http://www.newegg.com/Product/Product.aspx?Item=N82E16813157366
Look u can mount up to 7 cards .. but you need risers so u can use the psi 1 to the 16x ...
you can find here http://www.gobitgo.com/articles/1001/How-To-Correctly-Use-and-Install-PCI-E-Riser-Cables/


maybe you will need 2 psu for the 5x 280x .... yeah... 250x5 = 1250 .. i would suggest getting 2x 700W psu .. caz u need power for yourboard and cpu as well...

Get a decent Fan that goes up all those cards caz that will generate a huge amount of heat ...

I was writing that response before that was put up so I didn't see it!

 

[unknownofprob]

I'd still go with 4 R9 290's and if dual PSU's is good then go for it as it isn't that bad and dangerous. Dual 700-750 Watt PSU's for four of those cards is a decent wattage to power those cards well. But I like the solution of another poster and that was to have two PC's with 2-3 cards in each which will solve dual PSU's.

 

[Neverrazor]

Also Take alook at the 7790 Card they do 250 k/hash with 70 W so 3x of those do 750 k/hash with 210 W .... and they do not run as hot as 280x when mining

 

[unknownofprob]

Also Take alook at the 7790 Card they do 250 k/hash with 70 W so 3x of those do 750 k/hash with 210 W .... and they do not run as hot as 280x when mining

Block water coolers can solve cooling

 

[unknownofprob]

I'd take a look at a workstation motherboard with 4 PCI-E 16x slots.

 

[rolli59]

Mining!
In use each cards consume around 250watts around 350watts stress test http://www.techpowerup.com/reviews/Gigabyte/R9_280X_OC/24.html
Using multiple PSU's works if you jump the 24 pin ATX connector.

Yes I know that this will work... but do I risk the possibility of frying my system somehow? I've heard multiple PSUs isn't a good idea, what am I missing here? I don't see what the risk is.

It has been done and no more risk than anything else.

 

[joneustace]

Separate circuits might cause ground loop issues - and if a fuse/breaker blows on one line it might be bad for the system. Better off getting a 20A circuit or using the stove outlet.

Other than that, no major issues running dual PSU to a single outlet.

Interesting.... I'm installing the units close to the breaker box. I could easily install a 240v breaker onto it. Can I run a PSU on a 240v outlet here in Canada? Is that the same as euro power?

 

[giantbucket]

Other than that, no major issues running dual PSU to a single outlet.[/quotemsg]

Interesting.... I'm installing the units close to the breaker box. I could easily install a 240v breaker onto it. Can I run a PSU on a 240v outlet here in Canada? Is that the same as euro power?[/quotemsg]

Sure as long as the PSU has the right voltage switch on it (220/230/240 are all close enough and oftentimes the same actual thing). But if you're within reach, why not run a dedicated 20A line for them?

 

[wbmillerkc]

If I have one PSU connected to 2 of the cards and the Mobo, then the other PSU connected to the remaining cards, is this safe? If it isn't please be as specific as possible to explain why that isn't safe. I have a semi-electrical background. [/quotemsg]

I hope a you get an answer, I'm thinking the same thing on a litecoin set up I'm planning. I know you can hook up multiple PSU's, but I'm not sure you can in the config you're talking about. Here's a link that might help.
http://www.add2psu.com/

 

[giantbucket]

i would NOT use that tiny little thing to add a PSU. if that POS works like i think it does (connect extra PSU to 24pin, use 4pin to "add the power" to your existing system) then you'll probably burn a wire. people add a PSU to get more current, and shoving that extra current through just ONE simple 18AWG wire is not a good idea. it might be fine for adding 120W or 150W, but i wouldn't trust it to add 500W.

 

[wbmillerkc]

it might be fine for adding 120W or 150W, but i wouldn't trust it to add 500W.

Makes sense. It's been a while since I built my last system... (socket 7 mobd) and I haven't had to string PSU's togther like this in the past. With 5-6 r9 280's I can't buy a big enough PSU for a reasonable price. So.. back to the OP's orginal question. If I have a Gigabyte 990 MB, a 95watt CPU 8g of ram etc.. can I take my existing 550w PSU to power the MB/CPU/SSD etc, and have independent PSU's (probably 850w x2) powering the video cards?