Power, Temperature, & Noise

As was the case with gaming performance, we’ll keep our running commentary thin here. The Radeon HD 6950 1GB is virtually identical to the 2GB card, so other than a few watts power difference (which can easily be explained by being an engineering sample) the two are equals. It’s the XFX Radeon HD 6870 Black Edition that has caught our attention.

Radeon HD 6800/6900 Series Load Voltage
Ref 6870 XFX 6870 Ref 6950 2GB Ref 6950 1GB
1.172v 1.172v 1.1v 1.1v

While the XFX 6870 has the same load voltage as the reference 6870, between the change in the cooler and the higher core and memory frequencies power usage still goes up. Under Crysis this is 11W, and under FurMark this expands to 16W. Unfortunately this factory overclock has wiped out much of the 6870’s low power edge versus the 6950, and as a result the two end up being very close. In practice power consumption under load is nearly identical to the GTX 460 1GB, albeit with much better gaming performance.

Meanwhile this is one of the few times we’ll see a difference between the 1GB and 2GB 6950. At idle and under Crysis the two are nearly identical, but under FurMark the 1GB reduces power consumption by some 12W even with PowerTune in effect. We believe that this is due to the higher operating voltage of the 2Gb GDDR5 modules AMD is using on the 2GB card.

As far as temperatures go both cards are in the middle of the pack. The vapor chamber cooler on the 6900 series already gives it a notable leg up over most cards, including the XFX 6870. At 41C the XFX card is a bit warm at idle, meanwhile 78C under load is normal for most cards of this class. Meanwhile the 6950 1GB and 2GB both perform identically, even with the power consumption difference between the two.

Last but certainly not least we have our noise testing, and this is the point where the XFX 6870 caught our eye. The reference 6870 was an unremarkable card when it came to noise – it didn’t use a particularly advanced cooling design, and coupled with the use of a blower it ended up being louder than a number of cards, including the vapor chamber equipped Radeon HD 6970. The XFX 6870 reverses this fortune and then some due to XFX’s well-designed open-air cooler. At idle it edges out our other cards by a mere 0.1dB, but the real story is at load. And no, that’s not a typo in the load noise chart, the XFX Radeon HD 6870 Black Edition really is that quiet.

In fact at 41.4dB under load, the XFX 6870 is for all intents and purposes a silent card in our GPU testbed. Under load the fans do rev up, but even when doing so the card stays below the noise floor of our testbed. Compared to the reference 6870 we’re looking at just shy of a 14dB difference between said reference card and the XFX 6870, a feat that is beyond remarkable. With the same warning as we attach to the GTX 460 and GTX 560 – you need adequate case cooling to make an open-air card work – the XFX Radeon HD 6870 Black Edition may very well be the fastest actively cooled quiet card on the market.

Meanwhile for the Radeon HD 6950 1GB and 2GB, we’re once again left with results that are nearly indistinguishable. Under load our 1GB card ended up being .6dB quieter, an imperceptible difference.

The Test & Gaming Performance Final Words


View All Comments

  • Ryan Smith - Thursday, January 27, 2011 - link

    Apparently there are 2 Black Edition cards. The one we looked at is the newer of them (687A-ZDBC), whereas the old one used the reference cooler. I'm not sure the newer Black Edition has as widespread availability as the older one, but it's been available at Newegg for as long I've had the card in my hands. Reply
  • antifuchs - Saturday, March 5, 2011 - link

    That would be very interesting to note in the article - could help prevent some annoying mis-purchases: Newegg don't list the newer one (-ZDBC) as a "Black Edition", and searching for "black edition" will only find the reference-cooled card, whereas this article doesn't mention the full model number.

    I would almost have bought the loud reference edition one. Thank god I re-read the comments and re-did the search on Newegg one final time.
  • Hrel - Wednesday, January 26, 2011 - link

    So, when am I gonna start seeing 1080p in these charts; as that's really all I care about. I was hoping 2011 would be the year of 16:9 only, to my great dismay this is wrong. Please update soon, 16:9 has been the standard for like 2 years at this point, longer depending on how you look at it. Reply
  • AnnonymousCoward - Thursday, January 27, 2011 - link

    16:9 sucks. Reply
  • ibudic1 - Thursday, January 27, 2011 - link

    if you did share your experience.
    This is how you unlock...

  • erple2 - Thursday, January 27, 2011 - link

    The problem with this is that it's not guaranteed. While you can always flash back if problems arise, making buying decisions strictly based on what the card might be able to do (granted, there's not a lot of cards in the general review cycle that haven't shown that it can be unlocked) sounds an awful lot like "two in the bush". Reply
  • 7upMan - Thursday, January 27, 2011 - link

    RYAN: Hi Ryan, while I usually find AnandTech articles quite entertaining and informative, I always wonder why the f*ck professional editors won't get it into their head to test 2GB cards in areas where they belong to. Meaning: a 2GB vs. 1 GB card test should be about graphically overly intensive games and game mods, like the Half-Life 2 Fake Factory mod, or the STALKER Complete mod (Oblivion too has such mods). There are a number of other mods that put massive numbers of huge textures into the graphics RAM, and I think they should be the ones you need to test the cards with. After all, you can't expect games that were written with 1GB VRAM in mind to utilize the full power of double VRAM.

    So please, please run some tests with the above mentioned mods. Thanks in advance.
  • snuuggles - Friday, January 28, 2011 - link

    The chart for Stalker call of pripiate, is repeated on this page:


    it just shows the same chart twice...

    Also, canyou post an edit in the article itself with a link to the actual xfx card or a picture or something? The link you have currently seems to go to one with a stock cooler, and I don't want to just guess which one it is that you tested. Thank you!
  • snuuggles - Friday, January 28, 2011 - link

    woopsies! I didn't see the *multiple* pictures you posted of the card. But it would still be awesome to get a corrected link to the exact card, I'm still not 100% clear which one you tested. I apologize if I (again) missed this bit if information

  • Figaro56 - Friday, March 4, 2011 - link

    For the same price of $500 you can get a couple of HD 5870 Crossfire that will kick the GTX 580's teeth down it's throat. Reply

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