Do Two GeForce GTX 680s Beat Three GeForce GTX 660 Tis In SLI?

References
By Thomas Soderstrom
published

Power And Efficiency

Our overclocked hexa-core CPU pushes baseline power numbers fairly high, but we pushed them even higher by setting these graphics cards to run at their highest fan speeds. That extra cooling turned out to be necessary in order to get three highly overclocked GeForce GTX 660 Tis running in three-way SLI, particularly since the middle card's intake fans were stifled by the back of the bottom card. The cost of a 100% duty cycle ranged from 5 W on the stock GeForce GTX 680 2 GB to 20 W for three GeForce GTX 660 Ti cards in SLI. Under heavier GPU loads, the difference wasn't as significant.

The third GeForce GTX 660 Ti appears to idle down to around 18 W, while the second GeForce GTX 680 4 GB appears to idle down to around 25 W. Default fan speeds drop those numbers to around 12 W and 19 W, respectively.

The average performance chart could be a spoiler for the conclusion, but it's required for our efficiency calculation. Fortunately, we can still discuss some of the issues not easily identifiable from this chart, though.

Gigabyte’s overclocked 4 GB GeForce GTX 680 outperforms the stock 2 GB version by around 4% in our tests. Yet, higher power consumption nudges its efficiency gain down to 2%. A pair of Gigabyte’s 680s provides the best performance-per-watt, while high energy use keeps three GeForce GTX 660 Tis from scoring an efficiency lead.

Thomas Soderstrom
Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
49 Comments Comment from the forums
  • renz496
    off topic:

    when titan's review comes out?

    on topic:

    frankly i'm no multi gpu nor multi monitor user. but for the green camp if you want multi monitor gtx 660 ti 3Gb is a good choice if you want the cheap option. if you want more horse power while still on the cheap side then 7950 is the answer. (the latest game bundle from amd might also lean some people to buy amd cards)


    Reply
  • A sneak peak to the GTX Titain 6GBs. From the website "WCCF Tech"
    http://wccftech.com/nvidia-geforce-gtx-titan-pictured-gk110-finally-arrives-consumers-blasting-6-gb-memory/
    Reply
  • rantoc
    From my own experience I would rather go with 2x 680 as dual sli scales very well on about _all_ titles while tri/quad sli can be more of a gambling in performance - For titles where all the cards scale well its sure nice as hell - Where it does not you can even loose performance by adding a third/fourth card (even thoo that scenario gets less and less frequent).
    Reply
  • mcd023
    id like to see some benchies on metro 2033 with physx and DoF just for fun hahaha
    Reply
  • hero1
    Nice review, makes me consider taking 3x7950 instead of 2x7970. Would equal in price due to sales that are going on. But, maybe grab a Titan? I hope to see another review in 8 hrs featuring Nvidia GeForce Titan.
    Reply
  • mayankleoboy1
    Not the point of this article, but i noticed that a single gtx680 is a complete beast at 1080P.
    Also, it would have been interesting to see the CPU usage during the tests.

    Edit : A repeat of this article with the HD7000 cards should be performed, specially after the 13.2 driver are released.
    Reply
  • hero1
    mayankleoboy1Not the point of this article, but i noticed that a single gtx680 is a complete beast at 1080P.Also, it would have been interesting to see the CPU usage during the tests.Edit : A repeat of this article with the HD7000 cards should be performed, specially after the 13.2 driver are released.
    Yes same review for HD 7000 series should be given. Can't wait for that.
    Reply
  • merikafyeah
    I'd still go for a GTX 690 Hydro Copper. Overclock it and pwn while only taking two slots. SLI configs which take up all your slots seem highly inefficient and unappealing.
    Reply
  • esrever
    when are you going to switch to the new 3dmark?
    Reply
  • rmpumper
    Why do you say "higher/lower is better" in some graphs? Which is it - higher or lower?
    Reply