Minimum psu for 2 8800 ultras?

[Raikiri]

Isnt going Crossfire with 2 2900xt's faster? also cheaper, and i think you dont need the game to be CF enabled like SLI or something along those lines.

Why would two slower cards be faster?

Crossfire isn't exactly working very well with the 2900s at the moment either.

@OP: The Inifniti 720w should be more than enough.

 

[james.miller]

why do u need an 8800 GTX and 7300GT in the same pc?

i have two monitors and a 40" lcd


corsair demo'd a rig of the specs i mentioned running on a hx620. they will also freely tell you on their forums that its more than enough for 8800gtx sli. given the current draw of my own pc, i dont see why it would be a problem. i've always said have a little in reserve though, which is why i said 750-800 is more than enough

 

[Rroff]

no way. like i said, my pc draws 350w measures with profession equipment. its not possible!

That a constant or peak? most PSUs are rated for their peak power output... for 350 watt constant you'd really need a 500 watt PSU.

 

[james.miller]

that was the peak draw with 1 cpu core running superPI and running 3dmark at the same time. in fact, 389w was the peak draw for my pc, my 22" dell monitor and my router and modem all tested together!

my pc at the time of testing was this:

p5w dh deluxe
e6600 @ 3.3ghz
x-fi xtreme gamer
1x 8800gtx
1x 7300gt
2gb ddrII
2x 500gb hdds
1x 250gb hdd
2x 18x dvd-r's
1x 360Hd-dvd drive
1x imon ultra bay
1x akasa all-in-one card reader/fan controller thingy
8x 120mm fans


not even an average pc.

 

[helmutcheese]

http://www.pro-clockers .com/images/review/enermax%20infiniti/ps_infiniti_3_big.jpg (close gap at .com wont let me post here)

Please look at above small pic and tell me, what this means.

I read into it that it can run 3x current PCI-E 1.0 card with 150watt each (what cards would that be) or 1x PCI-E 2.0 (300watt)cards soon out + 1 PCI-E 1.0 (100watt) card

Not 100% sure what they mean by that.

 

[truebluecfc]

Why would two slower cards be faster?

Crossfire isn't exactly working very well with the 2900s at the moment either.

@OP: The Inifniti 720w should be more than enough.

I thought i saw a few benchmarks showing its faster and that crossfire scales way more than SLI, doesnt matter then.

 

[helmutcheese]

I cant remember but I think Crossfire does scale better, but there is swings and roundabouts, I think it had something to do with higher res or turning up AA+AF etc that Nvidia came back or vice versa, someone will chime in no doubt with more info.

 

[Rroff]

that was the peak draw with 1 cpu core running superPI and running 3dmark at the same time. in fact, 389w was the peak draw for my pc, my 22" dell monitor and my router and modem all tested together!

my pc at the time of testing was this:

p5w dh deluxe
e6600 @ 3.3ghz
x-fi xtreme gamer
1x 8800gtx
1x 7300gt
2gb ddrII
2x 500gb hdds
1x 250gb hdd
2x 18x dvd-r's
1x 360Hd-dvd drive
1x imon ultra bay
1x akasa all-in-one card reader/fan controller thingy
8x 120mm fans


not even an average pc.

Aslong as everything isn't running 100% maxed out your figure is pretty reasonable and realistic... if the CPU and both GPUs were maxed out drawing their rated power tho and the soundcard and motherboard also drawing 100% of their rated power you'd be pushing 380 watt easy without the rest of the system, as the HDDs and FANs combined even drawing their max would only put another 70-80watts ontop of that and the rest is pretty negligent your unlikely to manage to hit 500watts peak draw if you hammered the system beyond even extreme useage.

 

[james.miller]

the cpu and 8800 were running flat out. the motherboard, well. i think its hard to put in figure on power usage or duty cycle in percentage figures. i worked everythign as hard as i could, which was the best i could do really lol. just goes to show you though, pc's arent quite as power hungry as we're lead to believe

 

[Rroff]

the cpu and 8800 were running flat out. the motherboard, well. i think its hard to put in figure on power usage or duty cycle in percentage figures. i worked everythign as hard as i could, which was the best i could do really lol. just goes to show you though, pc's arent quite as power hungry as we're lead to believe

Indeed - the remnants of my old gaming PC (E6600, 680i, 4x HDD in RAID0) along with some crappy RAM and an 8500GT are quite happily running off a generic 350 Watt PSU...

 

[vairo]

800 would do i think ...

 

[Sean_UK]

Tbh there are some 600w PSU's with enough on the rails (Corsairs 620w model for example) to handle 2 of them GFX cards along with a fair bit of equip ontop. Nvidia's 'reccomended' PSU power is just an estimate thats takes into consideration the % of people out there who buy unbranded el-cheapo PSU's. Imo 800w is overkill in 'most' cases.

 

[chaparral]

Im looking to go sli with 2 8800 ultras on my new system that I'm building. Initially I'm buying one and will buy another when the prices drop, but from reading a guide on gamespot, it says that I'll need a minimum 900w psu to run these 2, anyone know if this is correct?

Still going.

Upto 3.5GHz now.

Jokester

Jokester said this is from only one 8800 ultra and overclocked quad cpu

 

[Sean_UK]

Quad and overclocked big time though , tbh the main poster hasent given us a big list of stats to work from with regards to the PC they going to be used with has he?...

 

[chaparral]

Quad and overclocked big time though ..

But it's only using one 8800 Ultra
And it not worth running SLI 8800 Ultra's without a quad CPU..

 

[Sean_UK]

4 cores oc + one ultra o/c versus 2 cores not o/c + 2 ultras stock, thats it's self will add a lot to the work load. Iirc Jokester has his PC pushed to the hilt...

 

[chaparral]

4 cores oc + one ultra o/c versus 2 cores not o/c + 2 ultras stock, thats it's self will add a lot to the work load. Iirc Jokester has his PC pushed to the hilt...

My own Power meter is showing up to a 400watt power draw with a single 8800gtx and C2D cpu....
And you need to allow headroom for overclocking as this about everyone with a system spec like this will try overclocking it at some stage..

 

[Sean_UK]

Measuring drain at the wall or PSU output?

 

[chaparral]

Measuring from wall...(Same as Jokester)

 

[ChrisD.]

I'd recommend the Etasis 750W or 850W. Both 8800 GTX SLI certified and Quad SLI certified. Read some reviews on them, you'll find they are very very good and rarely get mentioned.