GTX 460 SLI

[Azhrei]

Hi, I was wondering whether I would be able to run GTX 460 SLI on my current rig, or whether I would need to upgrade my PSU.

Intel Core i5 CPU 750 @ 2.67GHz
4GB Corsair XMS3 1600MhZ RAM
Corsair Extreme Series 32G - OS; 2x Seagate 7200.12 1TB; 1x Samsung 2TB; 1x Seagate 7200.12 500GB (4 HDDs, 1 SSD)
Gigabyte NVIDIA GeForce GTX 460 1GB OC (OC'd to 810/4200)
Gigabyte P55-UD3
Antec Earthwatts EA650 650 Watt PSU
8 System Fans

Thanks all.

 

[wa1]

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=110

Looking at the specs i think it's enough to run dual GTX460, but this PSU only came with 1 8pin pcie and 1 6pin pcie. You must use 2 molex 4pin to 6pin if you want to run the 2nd GTX460...

 

[nforce4max]

I have this psu in my other rig, it is a ok unit but far from perfect, I think that you will be able to get by but that is only by a margin knowing how this unit isn't their best. Runs rather hot well mine any way. Power wise the GTX460 isn't a hog till you start pushing the card to 900mhz+ then each could draw over 200w depending on the quality of each sample and the physical varm on each card.

 

[notty22]

I'm using that psu myself, with everything o/c. I had my doubts,
It runs fine, and have never had a weird 'event'.
I used Y splitters to avoid the whole molex (possible complications)
I use Everest and HW monitor to peek at the power rails and nothing 'bad' happens.
The rails do drop slightly lower than I have ever seen them before the 2nd gtx 460, but not more than .1
http://www.newegg.com/Product/Product.aspx?Item=N82E16812706014
is out of stock. Its sleeved and a little nicer, but this will work as well, you would need 2. To turn your 2 pci-e connectors to 4
http://www.newegg.com/Product/Product.aspx?Item=N82E16812198016&cm_re=8_pin_to_2_6_pin-_-12-198-016-_-Product
The PSU, does not seem to run warm. I do not have a hot environment and I don't usually run Furmark. But I have and ran Prime 95 at the same time. It all ran fine.

 

[Azhrei]

Thanks for the advice everyone - notty, could I ask, what are the possible complications you're talking about? (With molex to PCI-E, that is)

 

[notty22]

older design psu's sometimes pulled power from other than the 12v rail for molex connectors. That is not ideal, there is a sticky at johnnyguru.com that speaks of this issue : http://www.jonnyguru.com/forums/showthread.php?t=3990

The EA 650 is a multi rail design.

So there are no disadvantages to using a PSU with multiple +12V rails?

No! I wouldn't say that at all. To illustrate potential problems, I'll use these two examples:

Example 1:

An FSP Epsilon 700W has ample power for any SLI rig out there, right? But the unit only comes with two PCIe connectors. The two PCIe connectors on the unit are each on their own +12V rail. Each of these rails provides up to 18A which is almost three times more than what a 6-pin PCIe power connector is designed to deliver! What if I want to run a pair of GTX cards? It would have been ideal if they could put two PCIe connectors on each of those rails instead of just one, but instead those with GTX SLI are forced to use Molex to PCIe adapters. Here comes the problem: When you use the Molex to PCIe adapters, you have now added the load from graphics cards onto the rail that's also supplying power to all of your hard drives, optical drives, fans, CCFL's, water pump.. you name it. Suddenly, during a game, the PC shuts down completely.

Solution: To my knowledge, there aren't one-to-two PCIe adapters. Ideally, you'd want to open that PSU up and solder down another pair of PCIe connectors to the rails the existing PCIe connectors are on, but alas... that is not practical. So even if your PSU has MORE than ample power for your next graphics cards upgrade, if it doesn't come with all of the appropriate connectors, it's time to buy another power supply.

When this post was written by a very knowledgeable engineer , the Y splitters I pointed out to you, were not widely available.

 

[Azhrei]

Thanks a bunch for all of the advice - the trick is going to be finding splitters in Australia. :/

 

[Azhrei]

Best answer selected by Azhrei.