1000W PSU not enough for GTX 280 SLi...WTF?

[HOOfan_1]

From a review by a certain site.

Now remember that a single GTX 280 uses more power than a GeForce 9800 GX2, and thus two of them is going to use a lot of power. It was so much power in fact that our OCZ EliteXStream 1000W power supply wasn't enough. While the SLI system would boot and get into Windows, we couldn't actually complete any benchmarks.

By their own words they were able to boot up. By their own graph the entire system with GTX 280 SLi only used 508 Watts. Assuming AC power and the 85% efficiency that the EliteXstream is capable of...that is 433 Watts of DC being pulled by the system. So they established that the boot up draw wasn't too much, and considering the EliteXstream is capable of 960W on the 12V rail alone, and considering their measure of 508 Watts draw at load. Where do they figure that a fully functioning quality 1000 Watt PSU like the EliteXstream is not capable of running that system?

then consider this little nugget of wisdom

All of the power supplies on the GTX 280 SLI certified list are at least 1200W units

They better tell the people at SLi Zone that they were mistaken by putting the Xigmatek 1000 Watt and CWT 1000W on the dropdown lists then.

Edit, then they stated that the EliteXstream wasn't enough for 4850 Crossfire...after recording a 335 Watt draw at load. Obviously if the cards were not getting enough power then the PSU was deffective or something else was going on. How can they even begin to claim that a 1000 W PSU like the EliteXstream isn't enough for 2 4850? These cards use much less power than a 8800GTX.

[Sphere]

[Hutch]

The 280 GTX is extremely efficient when it's idle. More efficient than most mid-range cards suprisingly.

Those load numbers don't look right though, maybe they're not adding in something or their kill-a-watt is broken.

[Smirnoff]

Funny people. "Oh dear, the system draws well less than 500W from the PSU, but a 1000W isn't going to do the job for you". I mean.... Was there no logic at work? Early in the morning and no coffee maybe.

[HOOfan_1]

Originally Posted by Hutch

The 280 GTX is extremely efficient when it's idle. More efficient than most mid-range cards suprisingly.

Those load numbers don't look right though, maybe they're not adding in something or their kill-a-watt is broken.

I read about 15 reviews of the GTX 280 and those that did GTX SLi didn't show over 510-520 Watts of power consumption at load.

[jonnyGURU]

The transient loads is what kills the PSU.

But I still call shens. I can run a pair of GTX280's on the ES-800 with no problem. That said, it gets VERY CLOSE to the threshold of that PSU drawing as much as 800W from the wall. Each card drawing potentially 20A of power from the +12V rail.

But I wonder how they determined the problem wasn't enough power from the PSU? I've seen some problems with THE CARDS that one would think would point to the PSU, but it's a card problem...

Symptom:

Under heavy load, the screen goes blank and the power LED on the graphics card goes from green to red.

This is NOT a power supply problem. If the PSU was being overtaxed, the PSU would shut down. So that "certain site" needs to explain how their GTX280 failed to complete any benchmarks. There's word that this is a card problem, limited to a few units, and it may be corrected with a BIOS and/or driver update in the near future.

[Spectre]

Too lazy to look. Linky?

[HOOfan_1]

Originally Posted by Spectre

Too lazy to look. Linky?

Link to the article or link to a description of the power problem with the GTX 280?

If the former

A certain site

[jonnyGURU]

Yeah. They don't explain how they determined the power supply was inadequate. Could be a compatibility issue or could be a card problem. They need to lay out the symptoms they experienced.

Because the new cards have a power LED that turns red when there's no power to one of the connectors, a lot of people misinterpret a red LED as inadequate power. But the fact of the matter is, if the card experiences a problem and "shuts itself down" the LED will go red. This may or may not be a problem with the PSU at all. Like I said, if they disclosed that the system shut down completely, then I could agree that there may be a problem with the PSU.

[jonnyGURU]

FYI: Three GTX 280's running Vantage on an ES-800....







I took those pictures not to brag, but because I thought the rat's nest was funny. The PSU is "only" a BFG ES-800 which only has four PCIe. To get the other two I had to use two Molex to PCIe adapters. Since those PCIe adapters are 6-pin, there's also a 6-pin to 8-pin adapter in use. Major cluster fsck... but it works.