What's the max load for 2 x GTX 1080's?

[drago10029]

So I'm not in the market but I'm just curious. I have a 650W PSU with I believe 80% efficiency and I wanted to know if that could run 2 1080's?

according to a PSU calculator I used, it can. image below, what are your thoughts? thanks!

http://imgur.com/a/0aT3i

 

[R_1]

no image

 

[Math Geek]

doubt it. even a reference 1080 uses 200w of power and some aftermarket cards use 250w+

a high quality 650w psu might be able to handle 2 reference 1080's but i doubt it would handle 2 after market cards. this assumes top quality psu and i have no idea what model you have which may not even be a true 650w psu if it is low quality

 

[drago10029]

doubt it. even a reference 1080 uses 200w of power and some aftermarket cards use 250w+

a high quality 650w psu might be able to handle 2 reference 1080's but i doubt it would handle 2 after market cards. this assumes top quality psu and i have no idea what model you have which may not even be a true 650w psu if it is low quality

I found my PSU... http://www.newegg.com/Product/Product.aspx?Item=N82E16817151095

 

[drago10029]

no image

I updated my post, for some reason the site didn't embed the picture like it was supposed to.

 

[Math Geek]

doubt it. even a reference 1080 uses 200w of power and some aftermarket cards use 250w+

a high quality 650w psu might be able to handle 2 reference 1080's but i doubt it would handle 2 after market cards. this assumes top quality psu and i have no idea what model you have which may not even be a true 650w psu if it is low quality

I found my PSU... http://www.newegg.com/Product/Product.aspx?Item=N82E16817151095

that's a quality psu but it does not have the 2 8-pin connections you would need for 2 1080's. reference design uses an 8-pin while some aftermarket ones use 2 x 8-pins for 1 card!!

so that psu would not work even if it had the power. the 1070 also takes an 8-pin connection so that would be out as well. i'd look at more power for such a system as 650w would be pushing any psu too high for it to last very long like that.

and that calculator you used is not very good. it assumes reference 1080's for sure but then suggests that you can use a 605w psu which would be over 90% of capacity. not a good idea no matter what psu it is. 700w minimum would be needed to safely use 555w system. that's still 80% os the psu but is a lot safer. 750w or more would be ideal. and this is just for reference FE cards!!

notice that even though it says 605w it suggests the v750 to use. even the site knows that number is crazy low!!

 

[drago10029]

doubt it. even a reference 1080 uses 200w of power and some aftermarket cards use 250w+

a high quality 650w psu might be able to handle 2 reference 1080's but i doubt it would handle 2 after market cards. this assumes top quality psu and i have no idea what model you have which may not even be a true 650w psu if it is low quality

I found my PSU... http://www.newegg.com/Product/Product.aspx?Item=N82E16817151095

that's a quality psu but it does not have the 2 8-pin connections you would need for 2 1080's. reference design uses an 8-pin while some aftermarket ones use 2 x 8-pins for 1 card!!

so that psu would not work even if it had the power. the 1070 also takes an 8-pin connection so that would be out as well. i'd look at more power for such a system as 650w would be pushing any psu too high for it to last very long like that.

and that calculator you used is not very good. it assumes reference 1080's for sure but then suggests that you can use a 605w psu which would be over 90% of capacity. not a good idea no matter what psu it is. 700w minimum would be needed to safely use 555w system. that's still 80% os the psu but is a lot safer. 750w or more would be ideal. and this is just for reference FE cards!!

notice that even though it says 605w it suggests the v750 to use. even the site knows that number is crazy low!!

i agree thanks, I thought I might be cutting it close but glad I got another opinion.

 

[Math Geek]

no problem. at least red flags went up when you saw it. that shows a bit of knowledge on your part

many people would blindly follow the calculator and then wonder later why it did not work. but a single 1080 would be no problem at all with the psu. just note you only have a 6 and 8-pin pcie connection so the few dual 8-pin cards are out for that psu.