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
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  • peldor - Thursday, November 15, 2007 - link

    Only if it's a HT+Gaming PC. If it's just a HTPC, a 8600 or 2400 is still lower power and lower noise (with fanless options).
  • semo - Thursday, November 15, 2007 - link

    i'm still kicking myself for buying an ati 7500.
  • bryanW1995 - Thursday, November 15, 2007 - link

    I must be psychic. I called that about 30 minutes b4 article was posted. Anand must be reading my mind...:)
  • Anand Lal Shimpi - Thursday, November 15, 2007 - link

    Wanna go double or nothing? How do you think Phenom is gonna turn out? ;)

    Take care,
    Anand
  • chucky2 - Thursday, November 15, 2007 - link

    10% improvement over WHAT Anand? Come on, tell us... :)

    Chuck
  • Anand Lal Shimpi - Thursday, November 15, 2007 - link

    C'mon Chuck, one AMD launch at a time :)
  • GlassHouse69 - Thursday, November 15, 2007 - link

    Nice article :)

    3870 can run games decently on 1920x1200 resolutions. Being that i dont care about Crysis (oh no! taboo comment!) or xbox360 games on the pc (gears o war), it seems like it could be the card to get..... If the retailers do not price gouge. Waiting for newegg to inflate this one.

    It seems that the 3850 is the same card as the 3870 in many ways. Any attempt at oc'ing will be really fascinating. I wonder if 1 Gb of gddr4 will make this card more competitive. even 768 megs would be nice/adequate
  • Kougar - Thursday, November 15, 2007 - link

    Newegg has stock on three HD 3870 cards, all three are priced at $220 right now.
  • DrMrLordX - Thursday, November 15, 2007 - link

    I have to ask, was there any antialiasing in these benchmarks? I suspect not but I'd like to hear an answer anyway.

    The 3850 looks like a good card for overclockers, since it's just a downclocked 3870. At least it's nice to see that the 2900XT and 2900Pro have mostly been rendered obsolete by a cooler, quieter product that can be brought up to snuff with some overclocking.
  • Anand Lal Shimpi - Thursday, November 15, 2007 - link

    We included AA numbers with Oblivion (look for Oblivion AA in the graphs). The problem with AA these days is that most newer games don't really run well enough to have AA enabled and quality settings turned up (read: Crysis). While it's not a problem when testing pairs of 8800 GTXes, we felt it wasn't top priority for the more affordable and less powerful cards.

    That being said, I'll talk it over with Derek and see what we can do for some of our future articles.

    Take care,
    Anand

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