Multi-GPU Scaling: Two 3850s = One 8800 GTX?

AMD only sent us a pair of Radeon HD 3850s for this review (believe it or not, we had to beg to get a single 3870), so our only CrossFire numbers come from this setup. That being said, the performance is quite respectable:

Believe it or not, but a pair of these $179 Radeon HD 3850s actually gives you the same performance as a single GeForce 8800 GTX.

 Multi-GPU Scaling (2560 x 1600) Radeon HD 3850 CF GeForce 8800 GT SLI
Oblivion 1.7x 1.87x
Unreal Tournament 3 1.48x 1.66x

 

Scaling looks pretty good from the Radeon HD 3850, however it's still not as good as what NVIDIA is able to achieve with the 8800 GT. NVIDIA consistently achieves about 11% better scaling from one to two GPUs than AMD.

The other problem with CrossFire is that it simply doesn't always work, so a pair of 3850s is not necessarily a better option than a single 8800 GT or GTX. Case in point would be the two other games that we wanted to include here: Quake Wars and Call of Duty 4, both gave us lower frame rates with CF enabled than without. AMD's release notes for the Radeon HD 3800 drivers informs us that some applications may show a performance decrease with CF enabled, so we're not too surprised.

While it'd be nice to be able to purchase two cheap cards and get better performance than the best out there, there are simply too many caveats to really embrace the idea.

Out with the Old, in with the Mid-Range Power Consumption
Comments Locked

117 Comments

View All Comments

  • nowayout99 - Friday, November 16, 2007 - link

    I don't see a noise slide...

    But actually, Anand, noise may be a deciding factor for me. I'd really like to know what the cards sound like vs. the GT8800, particularly the 3870, if you guys could come back to it.
  • starjax - Thursday, November 15, 2007 - link

    What about testing with updated drivers? I understand that the HIS HD3870 cards are shipping with catalyst 8.43 drivers.
  • Comdrpopnfresh - Thursday, November 15, 2007 - link

    How do you guys decide the intermediate slopes of the graphs between them? Some of them look like cubic regressions...
  • Bram van der Heijden - Thursday, November 15, 2007 - link

    Just one thing i want to add.

    I think the last year AMD is really screwing up... dunno what there doing, but they aren't able to beat Intel, they aren't able to beat nVidia. Something went totally wrong over there. Marketing, Financial, Corporate launching strategies whatever... their screwing up.
  • Leadthorns - Thursday, November 15, 2007 - link

    Anand,
    How about the image quality? Some reviews claim its marginally better on the ati card than the 8800gt. Whats your take?
  • Bram van der Heijden - Thursday, November 15, 2007 - link

    Best Anand, and other readers.
    I find it startling to see you making an assumption that's already a fact: "The Radeon HD 3870 becomes even more attractive the more expensive the 8800 GT is and the opposite is true the cheaper it gets; if the 8800 GT 512MB was available at $219, then the 3870 doesn't stand a chance."

    I'm allready able to order Club3D 8800GT's 512MB for 208,- EURO's and even XFX's for about 212,45 EURO's... so thats even less in dollars. CLub3D is a company that builds good quality reference cards, so no suprises afterwards and XFX you all know.

    So... for such a good site as Anand's i find it a bit strange you are not aware of this, and living by the quote stated above... this allready blows away the 3870... though luck again AMD.

    Anyone interested in these cards haha, check out BEE-CT

    Regards,

    a Dutch bloke.
  • MrKaz - Thursday, November 15, 2007 - link

    There are rumors that in my country the ATI 3850 256MB version will cost 140€.
    160€ for the 512MB and around 200€ for the 3870.
    So this is in line with what you say.
    (all values have VAT)

    About the good luck, I think even with the slightly slower card the DX10.1 capabilities will be a selling point.
    Just ask the guys that bought the faster X800 over the 6800 and now can’t play some SM3 games.
  • jcromano - Thursday, November 15, 2007 - link

    One Euro is worth about 1.46 USD these days, no?

    So the 208 Euro card would cost about 304 USD, right?

    Jim

  • Bram van der Heijden - Thursday, November 15, 2007 - link

    Hmmm. back to school...

    That would mean 208/1.46 = 142 something...
  • Bram van der Heijden - Thursday, November 15, 2007 - link

    but it's not like that... damn.. ur right... that's pretty expensive...

    I was wrong... sry.

Log in

Don't have an account? Sign up now