Sapphire Toxic HD 7970 GHz Edition Review: Gaming On 6 GB Of GDDR5

By Igor Wallossek
published

Sapphire gives its new flagship graphics card 6 GB of very fast memory, compared to the mere 3 GB on AMD's reference card. Does this give Sapphire's Toxic HD 7970 GHz Edition a real-world speed boost? We connect it to an epic six-screen array to find out.

If You Like Sapphire's Vapor-X, Stick With The 3 GB Card

Sapphire's Toxic HD 7970 GHz Edition 6 GB is striking both for its exceptional performance and unexpected noise levels. Its 6 GB of very fast GDDR5 memory does help in certain workloads, but it’s barely noticeable normally at resolutions as high as 2560x1440. That's not enough of a differentiator for a graphics card that costs $600+. Really, it'd take a more competitive price tag to get us excited.

Don't get us wrong; the card is really fast. It would have been even better without AMD's GHz Edition changes, though, including PowerTune with Boost. We saw frame rates actually drop when the feature was pushed to its limits.

Lethal Boost does a good job of enforcing higher GPU and memory clock rates. Performance improves, which comes in particularly handy at higher resolutions. But we could do without the frequency modulation that doesn't even really help reduce power consumption. Also, the fan profile is too aggressive, making it loud.

Manual overclocking could have been very promising on this board, thanks to Sapphire's robust VRM, were it not for the card's inability to throttle down at idle with such a setting dialed in. Over time, the card heats up and makes noticeably more noise. It also dissipates close to 50 W doing nothing at all. This isn't Sapphire's fault, though. We caught the behavior in our Radeon HD 7970 GHz Edition launch coverage, caused by AMD's firmware.

As a result, manual overclocking really isn't a good option. The only practical way to use this board is the way Sapphire set it up.

One Toxic HD 7970 GHz Edition card can drive three or four monitors in a multi-display setup. A second board is almost assuredly needed for higher resolutions, making the 6 GB of on-board memory difficult to utilize. Professionals working in oil/gas applications are more likely to need lots of graphics memory, but they're using FirePro or Quadro cards. More purpose-built solutions exist for large video walls, which generally don't require enthusiast-class 3D performance.

All of that makes Sapphire's Toxic HD 7970 GHz Edition an answer in search of a problem. We can’t think of a usage scenario for which we’d recommend it. If you really dig the effort Sapphire put into its Vapor-X cooling solution, we recommend you check out the Vapor-X HD 7970 GHz Edition 3 GB card, and use the difference to take your better half out to a nice dinner.

Igor Wallossek
46 Comments Comment from the forums
  • Youngmind
    The 6gb of memory might not have much of an effect with only a single card, but I wonder if it will have a larger impact if you use in configurations with more graphics cards such as tri-crossfire and quad-crossfire? If people are willing to spend so much money on monitors, I think they'd be willing to spend a lot of money on tri/quad graphics card configurations.
    Reply
  • robthatguyx
    i think this would perform much better with a trifire.if one 7970 reference can handle 3 screens than 3 of these could easily eat 6 screen,in my op YoungmindThe 6gb of memory might not have much of an effect with only a single card, but I wonder if it will have a larger impact if you use in configurations with more graphics cards such as tri-crossfire and quad-crossfire? If people are willing to spend so much money on monitors, I think they'd be willing to spend a lot of money on tri/quad graphics card configurations.
    Reply
  • palladin9479
    YoungmindThe 6gb of memory might not have much of an effect with only a single card, but I wonder if it will have a larger impact if you use in configurations with more graphics cards such as tri-crossfire and quad-crossfire? If people are willing to spend so much money on monitors, I think they'd be willing to spend a lot of money on tri/quad graphics card configurations.
    Seeing as in both SLI and CFX memory contents are copied to each card, you would practically need that much for ridiculously large screen playing. One card can not handle multiple screens as this was designed for, you need at least two for a x4 screen and three for a x6 screen. The golden rule seems to be two screens per high end card.
    Reply
  • tpi2007
    YoungmindThe 6gb of memory might not have much of an effect with only a single card, but I wonder if it will have a larger impact if you use in configurations with more graphics cards such as tri-crossfire and quad-crossfire? If people are willing to spend so much money on monitors, I think they'd be willing to spend a lot of money on tri/quad graphics card configurations.
    This.

    BigMack70Would be very interested in seeing this in crossfire at crazy resolutions compared to a pair of 3GB cards in crossfire to see if the vram helps in that case
    And this.

    Tom's Hardware, if you are going to be reviewing a graphics card with 6 GB of VRAM you have to review at least two of them in Crossfire. VRAM is not cumulative, so using two regular HD 7970 3 GB in Crossfire still means that you only have a 3 GB framebuffer, so for high resolutions with multiple monitors, 6 GB might make the difference.

    So, are we going to get an update to this review ? As it is it is useless. Make a review with at least two of those cards with three 30" 1600p monitors. That is the kind of setup someone considering buying one of those cards will have. And that person won't buy just one card. Those cards with 6 GB of VRAM were made to be used at least in pairs. I'm surprised Sapphire didn't tell you guys that in the first place. In any case, you should have figured it out.
    Reply
  • FormatC
    Tom's Hardware, if you are going to be reviewing a graphics card with 6 GB of VRAM you have to review at least two of them in Crossfire.
    Sapphire was unfortunately not able to send two cards. That's annoying, but not our problem. And: two of these are cards are deadly for my ears ;)
    Reply
  • tpi2007This.And this.Tom's Hardware, if you are going to be reviewing a graphics card with 6 GB of VRAM you have to review at least two of them in Crossfire. VRAM is not cumulative, so using two regular HD 7970 3 GB in Crossfire still means that you only have a 3 GB framebuffer, so for high resolutions with multiple monitors, 6 GB might make the difference.So, are we going to get an update to this review ? As it is it is useless. Make a review with at least two of those cards with three 30" 1600p monitors. That is the kind of setup someone considering buying one of those cards will have. And that person won't buy just one card. Those cards with 6 GB of VRAM were made to be used at least in pairs. I'm surprised Sapphire didn't tell you guys that in the first place. In any case, you should have figured it out.Why not go to the uber-extreme and have crossfire X (4gpus) with six 2500X1600 monitors and crank up the AA to 4x super sampling to prove once and for all in stone.
    Reply
  • esrever
    The normal 7970s seem much better than the ghz edition.
    Reply
  • freggo
    FormatCSapphire was unfortunately not able to send two cards. That's annoying, but not our problem. And: two of these are cards are deadly for my ears
    Thanks for the review. The noise demo alone helps in making a purchase decission.
    No sale !

    Anyone know why no card has been designed to be turned OFF ( 0 Watts !) when idle, and the system switching to internal graphics for just desktop stuff or simple tasks?
    Then applications like Photoshop, Premiere or the ever popular Crisis could 'wake up' the card and have the system switch over.

    Or are there cards like that ?


    Reply
  • FormatC
    For noise comparison between oc'ed Radeons HD 7970 take a look at this:
    http://www.tomshardware.de/Tahiti-XT2-HD-7970-X-X-Edition,testberichte-241091-6.html
    Reply
  • dudewitbow
    freggoThanks for the review. The noise demo alone helps in making a purchase decission.No sale !Anyone know why no card has been designed to be turned OFF ( 0 Watts !) when idle, and the system switching to internal graphics for just desktop stuff or simple tasks?Then applications like Photoshop, Premiere or the ever popular Crisis could 'wake up' the card and have the system switch over.Or are there cards like that ?
    I think that has been applied to laptops, but not on the desktop scene. One of the reasons why I would think its not as useful on a desktop scene is even if your build has stuff off, the PSU is the least efficient when on near 0% load, so no matter what, your still going to burn electricity just by having the computer on. All gpus nowandays have downclocking features when its not being on load(my 7850 downclocks to 300mhz on idle) but I wouldnt think cards will go full out 0.
    Reply