View Full Version : Yet another GTX280 PSU question

12-16-08, 11:05 PM
I've read a few threads about this but am still a little confused.

Each card requires a 6-pin and an 8-pin connector, correct? My PSU is a Silverstone Zeus 850W (link (http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=5)). It has four 6-pin connectors. I want to run two 280's in SLI. Think my PSU will do OK using the supplied adapters that come with the cards (if I'm understanding the connections correctly)?

Also, has the overheating issue been resolved? Are the newer cards running at acceptable temps?


12-17-08, 03:48 AM
There are different kinds of connectors as you have seen, 6 pin, 6+2 pin and 8 pin.

6 pin should sustain 75w max while the 8 pin sustains 150w. a 6+2 is still 75w and they are not to be considered as true a true pci-e 8 pin.

That psu should be enough for two g260's core 216 but I'm not sure about the g280. I don't think it's enough performance difference to justify the cost difference, but thats just me.

12-17-08, 01:15 PM
So the 6+2 pin is still only 75 watts? If 150 watts is recommended for this connection, why does Nvidia certify PSU's that use the 6+2 pins for GTX280 SLI (i.e. the PC Power and Cooling Turbo Cool 1200)?

12-18-08, 04:09 AM
Good question, I've no idea to be honest. I was hoping some of the experts here would share some thoughts on the matter.

Been doing some searches on the matter but can't find that much (6 pin is 150 and 8 is 300w, I got it mixed up a bit)

However this post is rather interesting:

The Ultra X3 1000w won't work with a (single) gtx 280 for several people. due to the 6+2 pin. Too much volt drop. It does however work for some even with two g280's in sli.

12-18-08, 02:09 PM
well from my experience i have a thermaltake tough power 850 watt AND ITS NOT STRONG ENOUGH for 2 28o gtx. since i had problems with one of my cards and since then it had been rma,ed ive got a brand spanking new one sitting on the floor now not gonna use it till i get anew 1000 w psu.so the answer to yur question is no get a 1000w or above for hassle free setup.

just my 2 cents worth....

12-23-08, 08:37 AM
I have a 280 GTX coming for Christmas, but I 'examined' it before the wife wrapped it, and it comes with a 2 x molex to 8-pin connector. So if I'm right, you should be able to use a 6-pin directly from the PSU and 2 standard molex connectors and the adapter for a single card.

The the only thing that matters, I guess, is that I would expect the molex connectors would need to be on different loops of the PSU in order to get the required power. i.e. if you have a single 150w loop from the PSU with 4 molex connectors on it, that loop can only supply a maximum of 150w! You would need to use 2 separate 150w loops from the PSU to get 300w.

12-23-08, 09:07 AM
I have an OCZ GameXstream 700w with a one 6 pin and one 6+2 pin and it works perfectly with my single GTX 280.

12-23-08, 06:12 PM
I have a Silverstone 650 watt and it works fine with one GTX 280 ,the 8pin PCIe just has two more grounds .

12-23-08, 06:40 PM
Rosewill 950W runs two GTX280 SLI. Haven't seen better PSU for the price so far.

12-24-08, 04:38 PM
If you have a decent power supply and just need a little extra, then the Thermaltake 450watt VGA power express is a good choice .it fits in just one DVD slot and it has two 8pin PCIe connectors and two 6pin PCIe connectors and I know it works because I have ran both of my BFG GTX 280 OCX off of it ,but that is running it hard so I run my main GTX 280 off of my SilverStone 650watt and I run the second one off the 450watt VGA power Express,plus it is just $69.99 and has all the connectors you need.

12-25-08, 10:38 AM
That is pretty niffty and looks like a good way to go.

01-22-09, 08:47 AM
My OCZ 700W is from 2007 and it has only 2 6 pin PCI-x connectors. I am right now connected with one directly to the 6 pin slot. The second one is connected to the 8 pin adaptor. And then I am using 2 molex connectors to the 6 pin adapter which is then connected to the 8 pin adapter. Does so much looping cause any issues?

01-22-09, 09:36 AM
As far as the heat thing goes - my 295s are noticeably cooler than my 285s.