[HELP] 4- 280x's. Thinking of adding a 5th GPU.

[trademark]

Hey guys,

I currently have 4 - 280x's running on 2 psu's (750W and 850w gold series)  I am looking to add a 5th 280x or 290.  Do you think I'll be able to run 3 gpus on the 850w and put everything else on the 750w?  All suggestions are appreciated. Thank you. 

[Wipeout2097]

It's possible with a 280x. With a 290, probably not.  

However saying that a PSU is "850W gold" is not enough. Please state the brand and model.

Then you can undervolt the cards to make sure the PSU indeed tolerate 24/7 operation with yet some margin, to save power and reduce heat, at the expense of minimal and often no loss of hashrate.

[trademark]

It's possible with a 280x. With a 290, probably not.  

However saying that a PSU is "850W gold" is not enough. Please state the brand and model.

Then you can undervolt the cards to make sure the PSU indeed tolerate 24/7 operation, to save power and reduce heat, at the expense of minimal and often no loss of hashrate.

Thanks for the reply. Sorry, I have Cooler Master 850w and 750w Golds and Gigabytes 280x's.  Would these work?

[Wipeout2097]

It's possible with a 280x. With a 290, probably not.  

However saying that a PSU is "850W gold" is not enough. Please state the brand and model.

Then you can undervolt the cards to make sure the PSU indeed tolerate 24/7 operation, to save power and reduce heat, at the expense of minimal and often no loss of hashrate.

Thanks for the reply. Sorry, I have Cooler Master 850w and 750w Golds.  Would these work?

I insist; you actually need, for your own peace of mind, to actually state the brand and model down to specifications like amperage on the 12V rail(s). The most information you give, the better conclusion I can reach. Please provide accurate web link to the exact device, from http://www.coolermaster-usa.com/category.php?category_by=0&category_id=1709&category_name=850W%20-%201000W

I'm insisting on the issue because you may be able to add a 3rd 280x, but just barely. There is no margin for guesswork on my part and leave you holding the problem, if such arises. Even then, I'm not comfortable with an YES. It depends on your ambient temperature, if you want to mine very very demanding scrypt-n coins and others I have no control.

[NameTaken]

This video show 5 280X using only 1150W mining Scrypt-N so does that draw less power than Scrypt?

https://www.youtube.com/watch?v=EL2lRYVbQps

[trademark]

It's possible with a 280x. With a 290, probably not.  

However saying that a PSU is "850W gold" is not enough. Please state the brand and model.

Then you can undervolt the cards to make sure the PSU indeed tolerate 24/7 operation, to save power and reduce heat, at the expense of minimal and often no loss of hashrate.

Thanks for the reply. Sorry, I have Cooler Master 850w and 750w Golds.  Would these work?

I insist; you actually need, for your own peace of mind, to actually state the brand and model down to specifications like amperage on the 12V rail(s). The most information you give, the better conclusion I can reach. Please provide accurate web link to the exact device, from http://www.coolermaster-usa.com/category.php?category_by=0&category_id=1709&category_name=850W%20-%201000W

I'm insisting on the issue because you may be able to add a 3rd 280x, but just barely. There is no margin for guesswork on my part and leave you holding the problem, if such arises. Even then, I'm not comfortable with an YES. It depends on your ambient temperature, if you want to mine very very demanding scrypt-n coins and others I have no control.

Sorry, these are the models.  One is an 850w and the other is a 700w, not 750w as mentioned. Thank you for your help. Take care.

http://www.newegg.com/Product/Product.aspx?gclid=CO-w0dHsn70CFYeUfgodq74AZA&Item=N82E16817171079&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-Power+Supplies-_-N82E16817171079&ef_id=UumiOQAABVSzX330:20140320002418:s

http://www.amazon.com/Cooler-Master-V700-Modular-Certification/dp/B00CGY4ET6

[Wipeout2097]

You will be fine, that's an excellent 850W PSU.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=350

Undervolt the cards to 1000 ~ 1050 mV, monitor power usage with a Kill-a-Watt or similar, or at least use HwInfo software in the first few days just in case.

Anyway, get some coins 

[trademark]

You will be fine, that's an excellent 850W PSU.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=350

Undervolt the cards to 1000 ~ 1050 mV, monitor power usage with a Kill-a-Watt or similar, or at least use HwInfo software in the first few days just in case.

Anyway, get some coins 

Thanks a lot Wipeout2097 for the help.  Will do. Take care.