GeForce GTX 680, Part 2: SLI, 5760x1080, And Overclocking

Who needs sleep when you have caffeine? We take a second GeForce GTX 680 and run it in SLI against two Radeon HD 7970s. Then we add 5760x1080 benchmark results. Then we overclock our single-GPU flagships for a third comparison. Does our story change?

In the last week, I ate terribly, drank horrible, sugary things, and slept just enough to get myself into the lab to run benchmarks. Yesterday, as I polished off the last bit of text for GeForce GTX 680 2 GB Review: Kepler Sends Tahiti On Vacation, I truly thought I was in for a relaxing early weekend. But then the FedEx guy knocked. Oh, FedEx guy. The rumble of your truck is a bittersweet symphony. 

Hi, delivery man.Hi, delivery man.

Sure enough, I had a second GeForce GTX 680 on my hands. And I had already purchased a pair of Radeon HD 7970s. Really, there would be no excuse for not comparing the four boards.

I wanted to test 5760x1080 performance in my original piece, but simply ran out of time after the first three resolutions. Nvidia posted a new driver immediately after the launch, so I could also take the opportunity to verify that its NVEnc/MPEG-2 bug was fixed (it's not) (Update: Nvidia tells us that NVEnc is working, but that its CUDA cores are yielding better performance, masking the impact of its fixed-function hardware). Many folks asked to see a comparison between overclocked Radeon HD 7970 and GeForce GTX 680 cards, and that’d become possible as well.

And oh, there’s the issue of availability. We’ve been quick to slam AMD in the past for paper-launching its products, sending samples out to press with a note to expect hardware weeks later. Nvidia made it a point that GeForce GTX 680 would be available on launch day, and an early leak from Newegg provided confirmation enough. Unfortunately, the boards disappeared within hours of going on sale, and there are no longer any GeForce GTX 680s to buy. Nvidia says that another wave will hit our shores in early April (Update: Nvidia also claims that a quantity of boards are arriving to AIBs every day, so keep checking online. The "early April" guesstimate referred to what the company calls "going virtual," where its partners will start shipping their own customized designs and volume ramps up substantially. We'll be keeping an eye on the availability story in the meantime; as of 3/25, there are none available). But until then, everyone who didn’t set their alarm for the 6:00 AM embargo is just as stuck as the folks who had to wait weeks for Radeon HD 7970s, and that’s no fun.

Lastly, I made a mistake in yesterday’s story. In calculating the performance per watt index of the GeForce GTX 680, a single cell in Excel was reversed, and the 680’s performance ended up getting divided by the 7970’s power. The result was an overstatement of Kepler’s efficiency compared to Fermi, which has already been fixed in the launch story. GK104’s performance per watt outcome compared to GeForce GTX 580 is still significantly better than Tahiti’s—but not to the degree previously reported.

At any rate, today’s update should give you an even more complete picture of the GeForce GTX 680’s behavior and how it compares against AMD’s fastest single-GPU card. Let’s have a look at the card from EVGA enabling our SLI-based benchmarks, and then get on with the numbers!

Create a new thread in the US Reviews comments forum about this subject
This thread is closed for comments
107 comments
Comment from the forums
    Your comment
    Top Comments
  • cangelini
    weatherdudeYou know, I'm starting to wonder what the Tom's Hardware labs are like. I hope it has something to keep the staff sane as they run tests over and over again.Anyways, looks like the competition in the GPU world is going strong right now. To me both the GTX 680 and Radeon 7970 are fine pieces of work. The general compute performance of Tahiti is really really good though so will AMD really reduce the prices significantly below the GTX 680?Great review as usual. All your hard work is appreciated.

    If ever you're in Bakersfield, CA, you're welcome to drop by and check the lab out. It's like a gamer candy store, literally stacked with graphics cards higher than I can reach!
  • weatherdude
    You know, I'm starting to wonder what the Tom's Hardware labs are like. I hope it has something to keep the staff sane as they run tests over and over again.

    Anyways, looks like the competition in the GPU world is going strong right now. To me both the GTX 680 and Radeon 7970 are fine pieces of work. The general compute performance of Tahiti is really really good though so will AMD really reduce the prices significantly below the GTX 680?

    Great review as usual. All your hard work is appreciated.
  • bystander
    tacoslaveamds driver team needs to get off its ass i mean look at those crossfire results thats downright pitiful .

    What is wrong with their crossfire performance?

    You do have to look at the high resolution benchmarks to see actual crossfire results, as 1080p benchmarks are being bottlenecked by the CPU.
  • Other Comments
  • tacoslave
    amds driver team needs to get off its ass i mean look at those crossfire results thats downright pitiful .
  • bystander
    tacoslaveamds driver team needs to get off its ass i mean look at those crossfire results thats downright pitiful .

    What is wrong with their crossfire performance?

    You do have to look at the high resolution benchmarks to see actual crossfire results, as 1080p benchmarks are being bottlenecked by the CPU.
  • I am a PC
    It is quite clear that the Radeons are more powerful but that once again the Nvidia favoring benchmark suite once again favors Nvidia.
  • Anonymous
    Would like to see CUDA compute instead of openCL stuff. Something like Blender/Cycles benchmark.
  • cangelini
    I am a PCIt is quite clear that the Radeons are more powerful but that once again the Nvidia favoring benchmark suite once again favors Nvidia.

    If you were to hand-pick a suite to favor AMD, what would it include? :) You did notice the Radeons doing really well in Battlefield and Metro, right?
  • cangelini
    AgonothetaWould like to see CUDA compute instead of openCL stuff. Something like Blender/Cycles benchmark.

    Our Blender test is being working on right now--currently we're only utilizing the Tiles/Cycles engines for CPU reviews.
  • Anonymous
    My MSI 7870 came with Catalyst 12.3, so why use 12.2 if 12.3 is out there?
  • weatherdude
    You know, I'm starting to wonder what the Tom's Hardware labs are like. I hope it has something to keep the staff sane as they run tests over and over again.

    Anyways, looks like the competition in the GPU world is going strong right now. To me both the GTX 680 and Radeon 7970 are fine pieces of work. The general compute performance of Tahiti is really really good though so will AMD really reduce the prices significantly below the GTX 680?

    Great review as usual. All your hard work is appreciated.
  • cangelini
    sniper13xMy MSI 7870 came with Catalyst 12.3, so why use 12.2 if 12.3 is out there?

    Because it's not?
  • cangelini
    weatherdudeYou know, I'm starting to wonder what the Tom's Hardware labs are like. I hope it has something to keep the staff sane as they run tests over and over again.Anyways, looks like the competition in the GPU world is going strong right now. To me both the GTX 680 and Radeon 7970 are fine pieces of work. The general compute performance of Tahiti is really really good though so will AMD really reduce the prices significantly below the GTX 680?Great review as usual. All your hard work is appreciated.

    If ever you're in Bakersfield, CA, you're welcome to drop by and check the lab out. It's like a gamer candy store, literally stacked with graphics cards higher than I can reach!
  • noobalert
    Thanks for the Review, its been good reading! I can't wait for my new z77 ivy Bridge build. Now trying to hold off on getting cards is going to be tough.

    Next I want to see how the Dual GPU's from nVIDIA, & AMD fair, And see how long the Non-reference cards take to come out.

    Would love to see a 3D - 5760x1080 shootout with 2/3/4 7970's, and GTX 680's setups in the meantime.
  • master9716
    You made My day , 2 Reviews in 1 DAY!! WOW! I was waiting for this , I will probably go with Nvidia now since I was hopping they would release a card that can do 4k resolution on a single display for when I buy my SHARP 70" 4k tv. unless Amd comes out with a driver for 4k and lowers their price.
  • masterofevil22
    Nvidia MAX'd their new card out of the gate and AMD left theirs woefully underclocked...wtf are these two companies doing? Trying to create confusion?? OC'd 7970 ftw..
  • Energy96
    Would have been nice to see how 580's in SLI compare to 680's in SLI. Afterall most people who would buy 2 680's likely already have 2 580's and would like to know if the upgrade is worth it or not.
  • Anonymous
    I just want, the price of this come down
  • baracubra
    Again I really enjoyed this read over yesterday's review. It would have been nice to see percent performance scaling charts for SLI, but I guess if anyone desperately wanted them they could calculate themselves..

    Other than that great job, now just waiting for IB to drop. By then availability should be well sorted out..
  • sohei
    so at clock per clock is a draw?
    so guys buy what you want both cards are great, nvidia is a bit faster 7% average in gaming
    my conclusion is this. at gaming both cards are great
    at compute amd is better
    at power consumption Nvidia

    personaly i like 7970 is far better build with quality components
    in my country gtx 680 is more expensive so reality is different in prices...on paper nvidia is cheaper but ....
  • EzioAs
    I'd say both cards are in the same tier, unlike the difference between the 580 and 6970. The 7970 benefits more from overclocking and if crossfire scales well, 2 7970s performs equal to 2 680, although AMD really needs to work on the driver more as we see only a few games where it scales rally well. Pricing on the 7970 will have to drop although I hope to see less than $475 recommended in the article.

    Power issue isn't really a concern either as we've never seen any cards in the past delivering a great performance while consuming really low power. It doesn't rally matter that much whether one of them is more power efficient than the other because both of them are really power efficient cards. I'd say once the price drops, the 7970 and 680 will both be recommended cards, it all comes down to the buyer's choice and budget.

    Great article to answer all reader's feedback. Good job!
  • mayankleoboy1
    thanks for the reviews Chris ! :)

    just like to add that in the mediaespresso test, i would have like to see a SB 2500K/2600K for a reference. just to compare how the NVenc compares to the QuickSync engine.
  • mayankleoboy1
    its a shame that AMD has not yet got its drivers working right, with VEC and the other stuff still not ready for use...