Power Consumption

This was probably the most fun we had in testing for this review: measuring the power consumption of the 3-way SLI setup. We plugged the entire system into our Extech power meter and bet on how much power it'd use. Let's just say that NVIDIA isn't too far off with its minimum PSU requirements, see for yourself.

At idle, our 3-way SLI testbed drew around 400W of power. To put that into perspective, this is more power than any of our normal CPU or GPU testbeds under full load...just sitting at the Windows desktop. The third 8800 Ultra manages to pull an extra 100W without trying. Now let's see how much power this thing needs when playing a game.

We started with Crysis, which is normally our most stressful game test. Normally doesn't apply here though as Crysis didn't scale well from 2 to 3 GPUs, the third graphics card only improved performance by a few percentage points at our most playable settings, thus power consumption won't hit its peak.

Averaging 660W of power, the 3-way SLI system is now using over 2x the power of a normal gaming system outfitted with an 8800 GT. But it gets better.

Bioshock gave us the best scaling we saw out of the lot, and thus the 3rd GPU is working its hardest in this test, meaning we should be able to get our Extech to produce some stunningly high numbers.

And stunningly high we got. The 3-way SLI system averaged 730W in Bioshock, and get this, we even saw the machine pull over 800W from the wall outlet.

Configuration Idle Power Bioshock Load Crysis Load
8800 Ultra x1 217W 329W 337W
8800 Ultra x2 300W 475W 520W
8800 Ultra x3 388W 730W 660W

 

I was talking to Matthew Witheiler, our first dedicated graphics editor here at AnandTech, I told him how much power the system used under load and while idle. His response? "JESUS". "No", I said, "not even Jesus needs this much power".

Resolution and CPU Scaling Final Words
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  • IKeelU - Tuesday, December 18, 2007 - link

    When will this nonsense stop? It is perfectly reasonable for a game company to "permit" users to increase the detail if they so choose. On "high" the game looks and runs great on a sub-$400 video card. In fact, on "high" it looks better than anything out there, on any platform. At least with a "very high" setting available, the game will continue to look good a year from now when other games have caught up.
  • andrew007 - Tuesday, December 18, 2007 - link

    Uuuh... no, Crysis is not playable at "high" at any decent resolution on my 8800GT and 3.4GHz overclocked quad core Q6600. Decent being 1280 x whatever. And when you drop to medium, the game looks nothing special. Sure, there are a few areas that look great (forest level for example) but overall I was certainly not blown away. Unlike replaying Bioshock in 1920x1200 which this setup is capable of running very smoothly and which looks amazing in DX10. Quite simply, Crysis is one of the worst optimized games ever. At least it doesn't crash, that's something I guess. Looking forward to replaying it in 2 years. Come to think of it, it was the same with Far Cry, it took 2 years to be able to play that game with decent frame rates.
  • JarredWalton - Tuesday, December 18, 2007 - link

    There's nothing that says Crytek can't make a game where maximum detail settings exceed the capacity of every PC currently available. We've seen this in the past (Oblivion for one), and then a year later suddenly the game is more than playable at max settings on less expensive hardware. It doesn't appear that Tri-SLI is fully implemented for many titles, and considering the age of Crysis I'd expect more performance over time. Just like many games don't fully support SLI (or support it at all in some cases) at launch, only to end up greatly benefiting once drivers are optimized.

    FWIW, I'm playing Crysis on a single 8800 GTX at High detail settings and 1920x1200 with a Core 2 Duo 3.0GHz 2MB (OC'ed E4400). It might be too sluggish for online play where ping and frame rates matter more, but for single player I'm having no issues with that res/settings. It's a matter of what you feel is necessary. I'm willing to shut off AA to get the performance I want.
  • tshen83 - Tuesday, December 18, 2007 - link

    First of all, people who will fork over 1500 dollars worth of GPUs will want to play all games at the highest settings. That means highest AA and AF settings. I don't think you used AA and AF in your testing. It is almost pointless to play without AA for such a nice setup at 120fps(bioshock) where you are becoming CPU bound rather than GPU bound.

    Secondly, your Crysis test used 1920x1200. Why not 2560x1600? Why not 2560x1600 at 4xAA and 16xAF? Crysis at 1920x1200 without AA and AF are severely CPU bound in your case, as you have witnessed that a faster CPU gave you linear scaling.

    Third, there is actually no point of testing triple SLI at any other resolution other than 2560x1600. The target audience triple SLI is aimed at are those with 30 inch Cinema Displays.

    I think to be fair, you should rerun the benchmarks in a non-CPU bound situation with AA+AF on, you will see the proper scaling then.

    Thanks,

  • eternalkp - Tuesday, December 25, 2007 - link

    very good point Tshen

    I have a 30inch monitor.
    the 7900gtx was killing my frame rate.
    i was getting average 25fps @ 2560x1600, medium, 2X AA, 16X aniso...in FEAR Perseus Mandate.

    Just bought MSI OC 8800GTS G92 and very happy with it.

    Now i can crank up maximum graphic setting, 4X AA, 16X aniso @ average 40fps...very nice. :D

    Crysis is a hot engine, i only get 30fps @ medium, AA off.

    YES. what is the point of 3 GPU and have your AA/Aniso off?
    game will look like crap.
    Crysis recommends 4gb of ram.
  • kmmatney - Tuesday, December 18, 2007 - link

    "Third, there is actually no point of testing triple SLI at any other resolution other than 2560x1600"

    The point was testing at settings that are "playable". Who cares if the framerate goes from 8 to 12 @ 2560 x 1600. Its unplayable.

    I don't see how even an "enthusiast" wouldn't see triple SLI as a wate of money, though.
  • cmdrdredd - Tuesday, December 18, 2007 - link

    The point is that running 1600x1200 is really not anything you shouldn't be able to do with one card. Even 1920x1080 in many games is perfect. Showing off 10000000fps means jack, turn the res and AA/AF up and show us what it can push out.
  • defter - Tuesday, December 18, 2007 - link

    The author missed one advantage of 3-way SLI:
    Of course it doesn't make any sense to spend >$1500 on three 8800GTX/Ultras today, but what about those folks that already have a SLI 8800GTX/Ultras?

    For them adding a third card could be a reasonable upgrade option in comparison to replacing both cards with new G92 based cards.

    3-way SLI isn't for everyone, but it has its advantages.
  • praeses - Tuesday, December 18, 2007 - link

    I was under the impression that bioshock did not support AA in DX10. If that is indeed the case, that's hardly the fault of the benchmarker/reviewer.

    Also, I see much merrit in benchmarking at 1920x1200, its a much more common resolution and desktop-friendly resolution given the physical foot print of monitors. Lets be honest, many games aren't sitting 4ft from their displays. At 2-3ft a 24" display which most likely has 1920x1200 is much more comfortable for longer action based viewing. Ideally though they would have a lower dot pitch or simply higher resolution on the smaller screen.
  • tshen83 - Tuesday, December 18, 2007 - link

    One more thing: you are using Vista Ultimate 32bit with 4GB of memory. Since in 32bit, you have 3 768MB Ultras(2.4GB reserved just for video cards) , the system will only see about 1.5GB of memory. That is not sufficient system memory for high resolution benchmarks, especially Crysis.

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