Power Requirements


Current generation graphics cards are near the limit for how much current they are allowed to pull from one connection. So, of course, the solution is to add a second power connection to the card. That's right, the GeForce 6800 Ultra requires two independent connections to the power supply. The lines could probably be connected to a fan with no problem, but each line should really be free of any other connection.

Of course, this is a bit of an inconvenience for people who (like the writer of this article) have 4 or more drives connected to their PCs. Power connections are a limited resource in PCs, and this certainly doesn't help. Of course, it might just be worth it. We'll only make you wait a little longer to find out.

The card doesn't necessarily max out both lines (and we are looking into measuring the amperage the cards draw), but, NVIDIA indicated (in the reviewers guide with which we were supplied) that we should use a 480W power supply in conjunction with the 6800 Ultra.

There are a couple factors at work here. First, obviously, the card needs a good amount of power. Second, power supplies generally partition the power they deliver. If you look on the side of a power supply, you'll see a list of voltage rails and amperages. The wattage ratings on a power supply usually indicate (for marketing purposes) the maximum wattage they could supply if the maximum current allowed was drawn on each line. It is not possible to draw all 350 watts of a 350 watt power supply across one connection (or even one rail). NVIDIA indicated that their card needs a stable 12 volt rail, but that generally power supplies offer a large portion of their 12 volt amperage to the motherboard (since the motherboard draws the most power in the system on all rails).

Many people have been worried about heat generated by a card that requires two power connections. Just to be clear, we aren't drawing twice the power because we have twice the connection, nor are we generating twice as much heat. It's a larger chip, it draws more power, but it won't be clocked as high (with the 6800 Ultra version coming in at 400MHz as opposed to the 5950's 475MHz).

Customers who end up buying this card will most likely need to upgrade their power supply as well. Obviously this isn't an optimal solution, and it will turn some people off. But, to those who like the performance numbers, it may be worth the investment. And there are obviously rumors circulating the net about ATI's next generation solution as well, but we will have to wait and see how they tackle the power problem in a few weeks.
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  • mkruer - Wednesday, April 14, 2004 - link

    Well I hope this card is on par with ATi's or visa versa. ATi is planning to see their best at $500 pop and Nvidia is selling their at $400. How long to you think ATi is going to see their card for that price if the performance is virtually identical. Finally in the terms of the Power. Makes me wonder why PCI-Ex doesn’t include enough voltage from the socket? VPU's are getting to the point that they are just as powerful and complex as their CPU brethren, and will require the same power requirements as the CPU. Some one didn’t do their homework I guess. Well hears hoping that it will be in the next specification.
  • quikah - Wednesday, April 14, 2004 - link

    Can you post some screen shots of Far Cry? The demo at the launch event was pretty striking so I am wondering if PS 3 were actually enabled since you didn't see any difference.
  • Novaoblivion - Wednesday, April 14, 2004 - link

    Wow nice looking card I just hope the new ATI doesnt kick its ass lol
  • Rudee - Wednesday, April 14, 2004 - link

    When you factor in the upgrade price of a power supply and a top of the line CPU, this is going to be one heck of an expensive gaming experience. People will be wise to wait for ATI's newest flagship before they make any purchase decisions.
  • Pete - Wednesday, April 14, 2004 - link

    Nice review, Derek. Some impressive performance, but now I'm expecting more from ATi in both performance (due to higher clockspeed) and IQ (I'm curious if ATi improved their AF while nV dropped to around ATi's current level). I also have a sneaking suspicion nV may clock the 6800U higher at launch, but maybe they're just giving themselves room for 6850U and beyond (to scale with faster memory). But a $300 12-pipe 128MB 6800 should prove interesting competition to a ~$300 256MB 9800XT.

    The editor in me can't refrain from offering two corrections: I'm pretty sure you meant to say Jen Hsun (not "Jensen") and well nigh (not "neigh").
  • Mithan - Wednesday, April 14, 2004 - link

    Looks like a fantastic card, however I will wait for the ATI numbers first :)


    PS:
    Thanks for including the 9700 Pro. I own that and it was nice to see the difference.
  • dawurz - Wednesday, April 14, 2004 - link

    Derek, could you post the monitor you used (halo at 2048 rez), and any comments on the look of things at that monstrous a resolution?

    Thanks.
  • rainypickles - Wednesday, April 14, 2004 - link

    does the size and the power requirement basically rule out using this beast of a card in a SFF machine?
  • Damarr - Wednesday, April 14, 2004 - link

    It was nice to see the 9700 Pro included in the benchmarks. Hopefully we'll see the same with the X800 Pro and XT so there can be a side-by-side comparison (should make picking a new card easier for 9700 Pro owners like myself :) ).
  • DerekWilson - Wednesday, April 14, 2004 - link

    We are planning on testing the actual power draw, but until then, NVIDIA is the one that said we needed to go with a 480W PS ... even making that suggestion limits their target demographic.

    Though, it could simply be a limitation of the engineering sample we were all given... We'll just have to wait an see.

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