Geforce 280 GTX SLI & CoolerMaster M700 PSU Question

[adsldave]

Hello all

I have 2 geforce 280 gtx graphics cards & a cooler master m700 psu. The 280 gtx cards require a 6 pin & 8 pin pci power cable for each card & my psu only has 2 pci power slots (but is powerful enough for the both cards).

Is it possible to run 2 x 280 gtx cards using my psu ?, Hopefully with a 6 pin to 2 x 6 pin cable if that exists ?

Yes i'm a novice, Hence the question. Hoping to not have to buy a new psu.

 

[Leezy]

I can only just about run 1 280 on mine and it looks near enough the same.

I use both the 6 pins with a 2x6pin->8pin adapter for the 8 pin and then 2 molex's with a 2xmolex->6pin for the other.

It would take a stupid amount of cable for me to run SLI, like..

2 molex to one 6 pin, twice (so 4 molex) to make two 6 pins then a two 6 pins to 8 pin adapter just for the 8 pin! lol..

 

[adsldave]

I'm only using 2 of the 6 5 pin connections on my psu. Surely i can get a 5 pin to 6 pin pci-e cable & also a 5 pin to 8 pin pci-e cable ?

 

[jamiehavok]

i wouldn't run 2 280s on 700 watts. when i had a 280 and was looking into sli the general consesus was my 850 watt psu was only just ok.

 

[AgedIdiot]

I have the same PSU and I've got my doubts that you can run 2 x 280 's except ,possibly, by getting power to one via the 2 Pci-e connectors on the board and then using 2 converters (that are often given with gpu's) i.e. 2xmolex to one Pci-e X 2 (uses a total of 4 molex connectors) for the other gpu. BUT this might be too much for the psu and/or the molex connectors. ( the manual for the psu is somewhat sparse )

Even if it's possible (I have not seen the type of cable you mention) to connect both connectors on one card to one Pci-e slot on the psu and the connectors for the other card to the other slot I would think that you would overload the slot(s) !!

I'm def. NOT an expert and others with more tech. knowledge than myself may be able to provide you with a more definate reasoned answer to your ? but my answer can be best summarised by the statement ' As there are only 2 Pci-e slots on your psu ; you should only attach 2 Pci-e cables to it'- I'm sorry if I'm being somewhat negative but I do not believe in taking risks with Psu's ( you never know what damage they may cause if they fail!!)

 

[AMG]

a corsiar 700watt one probley would, but it will be cutting very close, I would make it 800 to be on the safe side

 

[adsldave]

I initially thought the same about the psu not being enough but 2 things changed my mind.

1. When i was reading the specs on my psu's box it stated that it can output 700w continuously or 840w for a short period (like a power surge i assume).

2. Then i read a review of my graphics card's in sli on guru3d where they measured the power being used on 100% usage of the pc & it was 530w being used (the pc was a similar setup to mine aswell). I must admit they recommend a psu of 750w minimum for sli of 2 x 280 gtx but also stated that the pc would not actually use that amount of power.
But 750w was recommended to keep the gaming experience stable while playing. As i would rather buy a few cables first as they would be cheap to see if it's stable anyway & if not then i would have to get another psu.

guru3d sli review
http://www.guru3d.com/article/geforce-gtx-280-sli-triple-review-test/2

Hopes it's ok to link to the review ?


P.S - Found this cable on ebay which would do the job for me

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310191403996&ssPageName=STRK:MEWAX:IT

 

[atmax1]

don't they come with the molex adapters like ati cards? if not im sure u can buy the adapters on places like ebay.

 

[adsldave]

don't they come with the molex adapters like ati cards? if not im sure u can buy the adapters on places like ebay.

Just added an ebay link a few seconds after you posted your cooment