Power, Temperature, & Noise

As we’ve discussed in previous articles, with the Fermi family GPUs no longer are binned for operation at a single voltage, rather they’re assigned whatever level of voltage is required for them to operate at the desired clockspeeds. As a result any two otherwise identical cards can have a different core voltage, which muddies the situation some. All of our GTX 460 cards have an idle voltage of 0.875v, while their load voltage is listed as below.

GeForce GTX 460 Load Voltage
Ref 768MB Ref 1GB EVGA 768MB #1 EVGA 768MB #2 Asus 768MB Zotac 1GB
0.987v
1.025v
0.987v
1.000v
0.987v
1.000v

Our cards end up ranging from 0.975v to 1.025v, a variance of 0.05v. The 1GB cards with additional functional units on average require more voltage to operate, with the lowest of our samples requiring 1.0v. Otherwise 3 of our 4 768MB cards require 0.975v.

We’ll start with idle temperatures. With an unofficial idle TDP in the 20W range, the GTX 460 series is fairly comparable to the Radeon 5850, but with a more breezy reference cooler. As a consequence we can see all of our GTX 460s edge out the rest of our cards here, with the EVGA and Asus cards coming in at 34C idle, while the blower-based Zotac card comes in a hair warmer at 35C. Even with a blower, these end up being the coolest mid-range or better cards we have ever tested, besting even the Radeon 5850.

As for load temperatures, we have a mixed bag depending on which card we're looking at. The reference-based EVGA cards do only slightly worse than 60C in Crysis, while Asus’s non-reference card gets that even lower thanks to a more aggressive fan. Zotac’s blower doesn’t fare so well here though, coming in at a still respectable but nevertheless higher 73C.

Our idle power numbers continue to lower the bar for GPUs of this performance class, although at this point we’re hitting the efficiency limits of our PSU at low wattages. Our 768MB GTX 460s end up sharing the 160W mark with the Radeon HD 5750, while for 1W more you have the Zotac 1GB card.

Meanwhile when looking at load power consumption, we see the cards seperate some due to their differences in memory capacity and factory overclocks.  The Asus card with its smallest overclock draws the least power under Crysis at 278W, while the EVGA card with its greater overclock comes in at 284W, and the 1GB Zotac follows at 289W. Under Furmark the same order is maintained, at 314W, 319W, and 325W respectively.

Finally we have our look at noise. With cool running cards we often have to look at fan noise to ensure that they aren’t accomplishing that trick by sounding like a jet engine, with some interesting results to see. At idle both the EVGA and Asus cards are hugging the 42dB sound floor in our testing environment, with the Asus card coming in slightly louder by 2.3dB. Meanwhile the Zotac GTX 460 is at entirely the wrong end of our charts. Blowers can be quiet, but the Zotac’s is not – at 51.4dB it’s simply a loud card. Unfortunately this kind of an idle noise level is going to put the card out of the running for a lot of buyers.

Load noise is more or less like our idle noise results. The reference-based EVGA card comes in the quietest at 46.9dB, while Asus’s card cracks 51dB as its tuned for cooling over noise. Unfortunately the Zotac card is once again the odd man out at 61dB, roughly as loud as our reference GTX 470 is. It’s neither cooler than our reference cards nor quieter, which doesn’t bode well for this stock-clocked card.

The Test Overclocked Performance
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  • VIDYA - Monday, July 12, 2010 - link

    you can overclock them.......you can compute with them.......you can easily scale their performance by just adding another card........and dont have to worry about memory and stuffs. LET ME SAY THIS GPU's have over taken the CPU's in more than many ways.....i would advice intel to develop a better larabee. Reply
  • Lord 666 - Monday, July 12, 2010 - link

    What gives Ryan? You have made your point clear (ad nauseum actually) about the several dollars differentiation between 768 and 1gb along with overclocking, but without a full picture of performance numbers, the review is still lacking.

    Is there still an NDA on the video performance and/or CUDA metrics as I noticed other sites do not have results either?
    Reply
  • Pessimism - Monday, July 12, 2010 - link

    The future you envision is more dependent on NVIDIA deciding to change their business practices and eliminate:

    -Faulty drivers that slip through QA with bad fan control, cooking their products to death
    -Poorly made chips that separate from their packaging with heat under normal operating conditions
    -Lying to their customer base about the existance of problems with their products
    -Refusing to give specific information to customers about exactly which products are defective
    Reply
  • DominionSeraph - Monday, July 12, 2010 - link

    I see ATI marketing is present and accounted for.

    Face it, Nvidia has a compelling product in the GTX 460. If it was priced $30 higher it would be nothing special. If it was 20% slower it would be nothing special. If it was a power hog like the GF100 it would be hard to recommend.
    But it's none of those things. Nvidia managed to sneak a good product in. Their ONLY one.

    Now maybe the 5850 will come back down to launch price ($259), or maybe even $249 which would bring its price/performance in line with the $229 GTX 460.
    Reply
  • mrmojo1 - Tuesday, July 13, 2010 - link

    "-Poorly made chips that separate from their packaging with heat under normal operating conditions"

    I have one of these in my ASUS g1s laptop. I had to have the MB replaced once already due to the nvidia GPU. Looks like it's gonna keep working until my warranty goes out in a month or two... fun stuff =/
    Reply
  • mrmojo1 - Tuesday, July 13, 2010 - link

    oh btw, I like both NVidia and ATI; i'm not an nvidia hater.

    Just a little pissed that a laptop I paid over $2000 for at the time was essentially defective from the start.

    tick tock tick....

    /rant
    Reply
  • irsmurf - Monday, July 12, 2010 - link

    Anyone thinking of going for a GTX 480 would be wise to consider SLI 1GB GTX 460's. 2D surround and better than GTX 480 performance for only $440 - $57.20 CB = $382.80 at TigerDirect.

    It is much more quiet, much more cool, consumes much less power, costs much less, and provides superior performance... what more could you ask for? This is the most kick ass card since the 8800GT. 5970 is TWICE the price... and you don't get SLI's superior scaling.
    Reply
  • irsmurf - Monday, July 12, 2010 - link

    I don't mean to say SLI GTX 460's will outperform the 5970. Reply
  • SantaAna12 - Monday, July 12, 2010 - link

    If the 5850 is the closest comp...then why no 5850CF benches? Reply
  • irsmurf - Monday, July 12, 2010 - link

    $400 vs $620? Doesn't sound like competition to me. Reply

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