Power, Temperature, & Noise

Last but not least as always is our look at the power consumption, temperatures, and acoustics of the Radeon HD 6790. Our power usage data should closely mirror any other 6790, but given the unique design of our card versus what AMD’s partners are going with, we can’t fully account for all the different designs.

On that note, at this point we do not know what the 6790’s default voltage is. None of our usual low-level tools recognize the 6790; it’s possible that AMD is using different controllers than on the 6800 series, or perhaps it’s related to drivers. In any case we believe it’s close to the 6870’s voltage of 1.17v, but we can’t measure it at this time.

Idle power consumption rarely changes among the different tiers of a GPU, so the fact that the 6790 pulls almost as much power at idle as the 6800 series should not come as a surprise. It does end up being worse than the GTX 550 Ti, but almost exactly alike the GTX 460.

Given AMD’s TDP numbers, we were expecting our power results to closely shadow our 6870 results. Instead we had a pleasant surprise: power consumption under Crysis is higher than the 6850, but not significantly so. In fact it’s still below the GTX 550 Ti even though it significantly outperforms said video card on this game, and even compared to the 5770 it’s not significantly worse for the 6790’s performance advantage. Not that it’s great to be consuming more power than a 6850 for less performance, but it could very well have been worse.

The situation under Furmark is even better surprisingly enough. The 6790 consumes less power than the 6850 here – not a ton less, but less. Perhaps more surprising is that compared to the 5770 it’s only consuming 3W more; this Barts chip may have a lot of functional units disabled, but that’s still quite remarkable, and is all the more proof of the optimizations AMD made for Barts compared to Cypress. This also makes it look exceptionally good versus the GTX 550 Ti and GTX 460 768MB, as it’s consuming 40-45W less.

With idle power consumption being identical to the 6800 series and using the same cooler, the idle temperature is similarly close.

Given the power numbers we saw earlier, the 6870’s cooler ends up being overkill for the 6790. As a result Crysis temperatures are quite low, although the fully exhausting cooler can’t keep up with the open cooler of the GTX 460. Then again our 5770 is an open cooler, and it’s still much warmer. Keep in mind that this is going to highly vary with the design of the cooler the partner uses though.

Temperatures under Furmark closely trend Crysis. An open cooler might be able to get the 6790 down to the low 70s.

Idle noise is identical to the 6800 series, as we’d expect.

Load noise is where the wheels begin to fall off on our 6790 sample. The card does so well with regards to power consumption and temperature, but noise is just as bad as the 6870. This undoubtedly is due to how AMD tweaked the 6790 engineering sample – which is to say it likely hasn’t been optimized much if at all since it won’t go into production. Given the power data we’ve seen the 6790 doesn’t need to be much louder than a 6850, so hopefully partner cards will reflect this. If not, the worst case scenario may very well be having all the noise of a 6870 and not nearly the performance.

Compute & Tessellation Final Thoughts
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  • deputc26 - Tuesday, April 05, 2011 - link

    On the last page.
    "and it would make NVIDIA think long and hard about what to do with what to do with the GTX 460 768MB"

    Oh and this comments section never remembers me despite always ticking the "remember me" box, (W7 Chrome)... annoying
    Reply
  • Belard - Tuesday, April 05, 2011 - link

    Why not just reduce the price of a 6850 a bit more... And calling it the 6830 wouldn't have hurt that much - since AMD totally screwup the model names of the entire 6000 series.

    Pretty much everyone knows the 6800s are cheaper and slightly updated 5800s.

    Think I'll wait until the 7000s come out... but that maybe in 2012.
    Reply
  • enterco - Tuesday, April 05, 2011 - link

    So, 6790 looks like a 5770 with a little performance improvement. For a 5770 / 450 owner it doesn't make any sense. Maybe for a new computer build on a specific tight budget. Reply
  • Arnulf - Tuesday, April 05, 2011 - link

    And 30+% the price. Why not go for the best price-performance at low overall price (which 6790 clearly isn't) when on extremely tight budget ? Reply
  • medi01 - Tuesday, April 05, 2011 - link

    Yet another round of "uhm", "oh", "but", "duh" about AMD product.
    In other news, we compare three 350$ AMD cards vs 3 500$ nVidia cards.

    Way to go, Anand.
    Reply
  • Mecavity - Tuesday, April 05, 2011 - link

    Oh, yay. Wouldn't be a proper article without someone complaining about an nVidia bias.

    A) The most expensive card included is an AMD...?
    B) The article is about a 150$ AMD card...? The case is being argued fairly, and the actual FOCUS is on comparing cards at the same level of pricing...?
    C) Critique works better if you state what you'd like to see included...?
    D) Derp.
    Reply
  • medi01 - Tuesday, April 05, 2011 - link

    The article is about 6790 and most of the conclusion page is about how 5830 sucks? (And how much did 5830 suck? Oh', they've dared to add more features while sacrificing a bit of performance and charge a bit more for it, how shameless... And this made it into the title of the product review. Pathetic.) Reply
  • strikeback03 - Tuesday, April 05, 2011 - link

    I noticed they gave this the exact same title they did for the 550Ti - "Coming up short at $150". And really the criticisms are the same - it is overpriced compared to both internal and external competition.

    How would you suggest they get excited over this? And how do you claim bias when one of the products they keep pointing to is the 6850?
    Reply
  • medi01 - Tuesday, April 05, 2011 - link

    Jesus Christ, AMD 3x350$ cards vs 3x500$ nVidia cards, where is bashing of the latter? (expensive, under performing and power hungry)

    How about if bashing, then bash both (who was there "duking out for performance king" eh?) if using softer words, then for all?

    Don't have balls to bash both anymore (stinky nVidia stories, *cough*)? DON'T BASH ANY!!!

    Oh, and last time I've checked, 460 was 160-200$ card (with MSRP 190$). And that was today.
    Reply
  • cknobman - Tuesday, April 05, 2011 - link

    I agree with ya.

    This article is focusing on the wrong things. Nvidia 460 768 MB is on the way out and has been publicly stated by Nvidia so that is going to leave a huge hole at $150 price point which is where the 6790 fits in. If you check out some of the other review sites the card performs pretty well (Anand your game library for benches sucks, HAWX - really? get with the times already!!!) plus the 6790 overclocks like a champ.

    Sure this is not the perfect $150 card but its most likely going to be the best there is in the immediate future.

    Im disappointed in this article.
    Reply

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