Advice on Power supplies

[Dropkickdragout]

Hey bitcoiners, I've got a bit of a problem here and was hoping you could assist me.  I'm planning on upgrading my single Nvidia GTX580 to 4 (yes four) AMD 6970's in my primary rig.  Now, the problem is, my power supply, while rock solid, is only 850W  and with a solid state, a hard drive, 12GB of ram, an i7 970, and an asus rampage extreme all in there, newegg's Calculator told me, very clearcut, that i should have 1650W... wait, what?  1650W?   they dont even come that big, so i'm turning to you miners, what the heck do i do?  do i stick with my 850W power supply and buy like 2 supplementary PSU's @ 450W each to power my gpu's?  I'm at a loss here and welcome your input.


Cheers!

[Takamsda]

Hey bitcoiners, I've got a bit of a problem here and was hoping you could assist me.  I'm planning on upgrading my single Nvidia GTX580 to 4 (yes four) AMD 6970's in my primary rig.  Now, the problem is, my power supply, while rock solid, is only 850W  and with a solid state, a hard drive, 12GB of ram, an i7 970, and an asus rampage extreme all in there, newegg's Calculator told me, very clearcut, that i should have 1650W... wait, what?  1650W?   they dont even come that big, so i'm turning to you miners, what the heck do i do?  do i stick with my 850W power supply and buy like 2 supplementary PSU's @ 450W each to power my gpu's?  I'm at a loss here and welcome your input.


Cheers!

To answer your question

Each 6970 will require 260W each. That's 1040W
And i7 970 drains way too much Wattage.


Minimum PSU Wattage:   1323 W
Recommended PSU Wattage: 1373 W*
Amperage (combined)

+3.3V   +5V   +12V
11.8 A   10.1 A   106.9 A

Minimum UPS rating: 1961 VA
Recommended UPS rating: ** 2600 VA

You'd want a Single Rail for +12V, cuz if not if anything dies there's a chance the PSU will bring the rest with it.

Corsair CMPSU-1200AX is a Single Rail PSU with 100A. What you're asking is impossible.

I'd suggest to drop either the i7 CPU or one of the 6970. No can do with your current set-up.

You'd like to have something that hits no more than 90A. Don't even bother with multi Rail PSUs.

I hope this will help you.

Tip me if you'd like my post!

[qed]

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

[Dropkickdragout]

ah, i understand what you're saying...well...that really stinks.   I have to ask though, if i bought le-*ts say....2 of these http://www.newegg.com/Product/Product.aspx?Item=N82E16817104054 and ran 2 cards per secondary psu, would that work?


edit nevermind, just realized that the supplementary psu is too small to support 2 of those cards./ >.> fek!

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

 that sounds risky

[Waltibaba]

ah, i understand what you're saying...well...that really stinks.   I have to ask though, if i bought le-*ts say....2 of these http://www.newegg.com/Product/Product.aspx?Item=N82E16817104054 and ran 2 cards per secondary psu, would that work?


edit nevermind, just realized that the supplementary psu is too small to support 2 of those cards./ >.> fek!

I'd suggest you get 2 XFX 750W psus, those are great value for money. Even two different ones where the combined 12V rails are over 105A and the ripple/noise are bearable (i.e. no coolermaster, sharkoon, rosewill, etc. etc.), because you'll be stressing those psus quite a bit (especially if you are planning to OC). In that case, ripple and noise are at a peak and can shorten the lifetime or even directly cause instability/damage your components.
Also you might want to consider two different power psus, depending on how you split up CPU/GPU load.

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

  I'm running a 6950 + 5830 with an XFX 850W hahaha. Talk about overkill...

[stellan0r]

or you get the smallest CPU possible for your mainboard (maybe even one of the energy saving low power ones) and buy an Enermax Revolution 85+ 1250W - one of the best you can get (yes its pricey but worth its money!)
this should be enough for your 4 cards.

[qed]

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

 that sounds risky

The only risk decreasing clock and voltage is that your system might freeze, you can't damage anything.

[kokojie]

I'm running 3 x 6970 on a 1000W XION PSU, with a 95W quad core CPU. I'd imagine a 1500W PSU would be more than enough for your PC, you can probably get away with anything above 1300W

[computerparts]

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

 that sounds risky

The only risk decreasing clock and voltage is that your system might freeze, you can't damage anything.

You seem to be misinformed. Undervolting anything introduces risk of long term damage.

[computerparts]

Hey bitcoiners, I've got a bit of a problem here and was hoping you could assist me.  I'm planning on upgrading my single Nvidia GTX580 to 4 (yes four) AMD 6970's in my primary rig.  Now, the problem is, my power supply, while rock solid, is only 850W  and with a solid state, a hard drive, 12GB of ram, an i7 970, and an asus rampage extreme all in there, newegg's Calculator told me, very clearcut, that i should have 1650W... wait, what?  1650W?   they dont even come that big, so i'm turning to you miners, what the heck do i do?  do i stick with my 850W power supply and buy like 2 supplementary PSU's @ 450W each to power my gpu's?  I'm at a loss here and welcome your input.


Cheers!

To answer your question

Each 6970 will require 260W each. That's 1040W
And i7 970 drains way too much Wattage.


Minimum PSU Wattage:   1323 W
Recommended PSU Wattage: 1373 W*
Amperage (combined)

+3.3V   +5V   +12V
11.8 A   10.1 A   106.9 A

Minimum UPS rating: 1961 VA
Recommended UPS rating: ** 2600 VA

You'd want a Single Rail for +12V, cuz if not if anything dies there's a chance the PSU will bring the rest with it.

Corsair CMPSU-1200AX is a Single Rail PSU with 100A. What you're asking is impossible.

I'd suggest to drop either the i7 CPU or one of the 6970. No can do with your current set-up.

You'd like to have something that hits no more than 90A. Don't even bother with multi Rail PSUs.

I hope this will help you.

Tip me if you'd like my post!

lol wut. This post is completely bogus. Please do some research before misinforming others. First off you can only estimate how much a gpu will draw, it is impossible to know exactly what it will draw. The only thing that can be measured accurately is the total wattage pull from the socket. Second, there is ZERO difference between multi rail and single rail. With single rail you don't have to worry about balancing the draw over the rails, that's it. Third, it is very much possible for what he is asking. Two GTX 295 which draw more than four 6970's can be powered in that rig with a certain 600w psu with no problems. It has been done before. Google it. However, he would do fine with any psu that has at least 80 amps on the 12v rails to allow headroom for overclocking.

[sc8nt4u]

Here are some real world figures from earlier today while using a kill-a-watt meter

Using Phoenix -phatk

2-card 100% - 590w+/-10w
1-card 100% - 355w+/-5w (2nd card removed)
1-card idle    - 152w+/-5w

Sempron 140
MSI 890FXA-GD70
1x2GB DDR3 1066mhz
Kingston SSD 30GB
2x 6970 Stock
Xion 1250w PSU ~ 86% efficiency @ 600w
Windows 7 x64

[qed]

Underclock and undervoltage the cards, i'm running a 500W PC with 4 unlocked 6950.

 that sounds risky

The only risk decreasing clock and voltage is that your system might freeze, you can't damage anything.

You seem to be misinformed. Undervolting anything introduces risk of long term damage.

Did you read undervoltage?

[qed]

lol wut. This post is completely bogus. Please do some research before misinforming others. First off you can only estimate how much a gpu will draw, it is impossible to know exactly what it will draw. The only thing that can be measured accurately is the total wattage pull from the socket. Second, there is ZERO difference between multi rail and single rail. With single rail you don't have to worry about balancing the draw over the rails, that's it. Third, it is very much possible for what he is asking. Two GTX 295 which draw more than four 6970's can be powered in that rig with a certain 600w psu with no problems. It has been done before. Google it. However, he would do fine with any psu that has at least 80 amps on the 12v rails to allow headroom for overclocking.

TDP of a GTX 295: 289 W
TDP of a HD6970: 250 W

Two GTX 295 are 578W and four HD6970 are 1000W. Is 578 less than 1000? Powering a 1000 W video card system with a 600W PSU sounds great. Single and multi rail systems are different especially if you push your system to the overclock limit.

The troll is strong in this guy.

[hawks5999]

If it's for mining, just go 45w sempron for the cpu. I've got 3 6950's on one board and 4 6790's on another 1200w works on both.