Is this PSU better for 3 x GTX 260 .....?

[kayawish24]

hello........!

i am want to ungrade my power supply to Chieftec CFT-1200G-DF 1200 Watt...but i dont know that the +12v rails be enough to run my Overcloked i7 950 @ 4Ghz and OC 3 x GTX 260 Core 216 3 way SLI.the specs of PSU in which i am intrested is..

Energy Efficient 80 PLUS Certified

 

80 PLUS Certified

Efficency > 80%

+3,3V 30 A

+5Vsb 6 A

+5V 30 A

+12V1 20 A

+12V2 20 A

+12V3 25 A

+12V4 25 A

+12V Total 90 A

-12V 0,8 A

more is here: http://www.newegg.com/Product/Product.aspx...1200G-DF%201200

 

my curent system is:-

 

CPU: Intel Core i7 950 @ 4GHz 1.36v 24/7 * prime95 stable *

Cpu Cooler: Thermaright 120 ULTRA Xtreme with 2 Fans

Board: ASUS P6t6 Revolution

Mem: 6GB Triple Channel DDR3 Corsair XMS3 1600MHz 8-8-8-24

GPU: Nvidia 3 x XFX GTX 260 Core 216 3-WAY SLI @ 715/1270/1431 (Core/Memory/Shader)

HDD: 640GB S-ATA Seagate Baracuda 32 Mb Cache 7200 Rpm

Sound: SoundMAX Full HD 7.1 Channel

OS: Windows Vista Ultimate SP1 x64 *Activated*

PSU: CORSAIR TX-850 Watts

Monitor: View Sonic 24" VA2413wm LCD

 

i dont think that my curent PSU corsair 850 watts can handle my curent setup....please help me

[paulktreg]

Three GTX260's is only about 400W so add the mobo, cpu, etc., and your TX850W will still easily supply the necessary power. My only reservation is your lack of 6 pin PCI-E connectors and the use of adapter cables which would have to be done via the 4 pin peripheral connectors, which I personally don't like to see especially if you are going to try and push the cards a little.

 

The power supply you have in mind certainly has more than enough power and connectors but with only four 12V rails and five heavy loads, cpu, mobo and three graphics cards something is going to be slightly out of balance. I can't find any decent reviews either so it's hard to give you an informed opinion on the Chieftec.

 

I think a better option is to stick with a single 12V rail power supply. I know this may sound strange but if funds permit then have a look at the HX850W. If it's anything like the HX750W and I see no reason why it shouldn't be, it will do the job nicely and has the six 6+2 PCI-E connectors you require. Perhaps an HX1000W if you want plenty to spare.

 

The Corsairs are just my suggestions but I do think you would be better of with a single 12V rail power supply and six 6 pin PCI-E connectors of at least 750W but I think you'll probably have to go 850W+ for the necessary PCI-E connectors. Just have a look round and see what's out there and let us know what your looking at we'll try to help.

 

Hope this helps.

 

Cheers

 

Paul

Edited August 4, 2009 by paulktreg

[Verran]

The Corsairs are just my suggestions but I do think you would be better of with a single 12V rail power supply

I completely agree. If you go with a split-rail power supply you're going to be at a much higher risk of over-drawing one rail and causing shutdowns. With a uni-rail design, that won't happen. Usually it's not a big deal but with three video cards, I'd say it would REALLY benefit you to go single-rail.

[Mikesnow]

If your going 1200w i'd get the ZW1200M just remember to flip the switch on the side to turn it into a single 12v rail with 95a. It is a bit pricey, but it is a very good PSU and 100% modular. The HX1000W is also a very good PSU as well, and is rather cost effective, but lacks the 100% modular design, and some of your cards will need to share 12v rails. Here is a diagram of how you would have to setup the connectors to make it work, I have this PSU currently running 2 gtx 280's and a core 2 duo setup, but didn't feel comfortable with it for the i7 975 and 3 x gtx280's I am upgraded too (Still waiting on the damn Corsair Obsidian 800D), so I got a 1500w Silverstone strider series, which was prolly a complete waste of money, but at least I know I have enough power. I am sure the cheiftec can handle the load. I guess what people are trying to point out is that some rails maybe running at full load versus others at say 20% load, and what effects that might have on the PSU down the road. You may also check out SLI-PSU Compatability list and check some of the ones out there listed for the 3x gtx260's.

[xly15]

I would keep that corsair tx-850 watt. That is all you will need for a tri GTX260 setup. Plus the single rail design is better.

[paulktreg]

If your going 1200w i'd get the ZW1200M just remember to flip the switch on the side to turn it into a single 12v rail with 95a. It is a bit pricey, but it is a very good PSU and 100% modular. The HX1000W is also a very good PSU as well, and is rather cost effective, but lacks the 100% modular design, and some of your cards will need to share 12v rails. Here is a diagram of how you would have to setup the connectors to make it work, I have this PSU currently running 2 gtx 280's and a core 2 duo setup, but didn't feel comfortable with it for the i7 975 and 3 x gtx280's I am upgraded too (Still waiting on the damn Corsair Obsidian 800D), so I got a 1500w Silverstone strider series, which was prolly a complete waste of money, but at least I know I have enough power. I am sure the cheiftec can handle the load. I guess what people are trying to point out is that some rails maybe running at full load versus others at say 20% load, and what effects that might have on the PSU down the road. You may also check out SLI-PSU Compatability list and check some of the ones out there listed for the 3x gtx260's.

 

The Silverstone power supplies are beyond doubt great units but a little on the expensive side if you ask me.

 

Flipping the switch will not give you 95A on the 12V rail, 95 x 12 = 1140W, well it will but leave only 60W for the 3V3 and 5V rails!

 

Who needs 100% modular design? I cannot, and never will, see the point of making the 20/24 pin motherboard and/or the EPS12V/ATX12V connectors modular, everybody needs them!

 

You'll have enough power alright with the 1500W because you'll never pull more than 550W (+ the rest) with 3 x GTX280's.

 

Cheers

 

Paul

Edited August 4, 2009 by paulktreg

[paulktreg]

I would keep that corsair tx-850 watt. That is all you will need for a tri GTX260 setup. Plus the single rail design is better.

 

Yes it has enough power but you need two more 6 pin PCI-E connectors.

 

Where are you going to get these from?

 

Cheers

 

Paul

[Bosco]

You'll have enough power alright with the 1500W because you'll never pull more than 550W (+ the rest) with 3 x GTX280's.

Paul are you sure thats correct? Or are you basing that off a lowerend system? I pull 482 watts at full load on my I7 280 SLI system. I think Frank gets over 500 on his just wondering on your thoughts on that

[paulktreg]

Paul are you sure thats correct? Or are you basing that off a lowerend system? I pull 482 watts at full load on my I7 280 SLI system. I think Frank gets over 500 on his just wondering on your thoughts on that

 

(+ the rest)! Edit: Sorry perhaps a bit misleading, 550W for just the gfx cards.

 

Lets give it another 250W for the rest and thats 800W for a complete tri SLI GTX280 system running at full whack!

 

Cheers

 

Paul

Edited August 4, 2009 by paulktreg

[Verran]

Who needs 100% modular design? I cannot, and never will, see the point of making the 20/24 pin motherboard and/or the EPS12V/ATX12V connectors modular, everybody needs them!

Thank you so much for saying this! 100% modular is such a silly thing to design and even sillier to seek out. Why should the 20/24 pin connector be modular? Why would you ever not use that? How is that feature useful? I have my reservations on any form of modularity, but 100% is just definitely silly to me.

 

I still think the HX850 single-rail is the way to go.

[paulktreg]

Thank you so much for saying this! 100% modular is such a silly thing to design and even sillier to seek out. Why should the 20/24 pin connector be modular? Why would you ever not use that? How is that feature useful? I have my reservations on any form of modularity, but 100% is just definitely silly to me.

 

I still think the HX850 single-rail is the way to go.

 

Let's take it a step further. Why should the SATA power cable be modular? Everybody (nearly) needs at least two I would imagine?

 

Cheers

 

Paul

[Mikesnow]

Flipping the switch will not give you 95A on the 12V rail, 95 x 12 = 1140W, well it will but leave only 60W for the 3V3 and 5V rails!

 

Right so shouldn't it be

 

12 x 95 = 1140watts

3.3 x 28 = 92.4watts

5 x 30 = 150watts

1140 + 92.4 + 150 = 1382.4watts

 

I don't think most PSU manufacturers rate their continuos power output based solely on the 12v power output, it's the overall?

 

reguardless in my case the gtx280's draw 25a each so your looking at roughly 300watts each so thats 900watts in just graphics cards add another 150watts for and avg cpu and your at a 1050watts before anything else, now under normal circumstances you won't see that kinda draw but during gaming, OC'ing and benching, your going to want to make sure you have enough imo. I'd rather spend a little extra money now and have more then enough so my PSU isn't working at 100% load constantly, which is just going to lead to a faster fail time versus a psu running at 70% load.

 

I am not sure what the gtx260's draw current wise but if they are any where close to the 280's with a heavy oc on the gfx cards and cpu the hx850 would be a fail imo, in fact the reason i didn't stay with the hx1000w is because people are blowing them out with 3 way sli setups and i7's when overclocking them, which might be why it hasn't earned a 3 way sli cert yet, it has the connectors for it tho.