Today is all about the Radeon HD 4870 X2, the same card we previewed last month but AMD is quietly announcing a few other products alongside it. The 4870 X2, internally referred to as R700, is a pair of RV770 GPUs on a single card - effectively a single-card, Radeon HD 4870 CrossFire (hence the X2 moniker). Like previous X2 cards, the 4870 X2 appears to the user and the driver as a single card and all of the CrossFire magic happens behind the scenes.

  ATI Radeon HD 4870 X2 ATI Radeon HD 4870 ATI Radeon HD 4850
Stream Processors 800 x 2 800 800
Texture Units 40 x 2 40 40
ROPs 16 x 2 16 16
Core Clock 750MHz 750MHz 625MHz
Memory Clock 900MHz (3600MHz data rate) GDDR5 900MHz (3600MHz data rate) GDDR5 993MHz (1986MHz data rate) GDDR3
Memory Bus Width 256-bit x 2 256-bit 256-bit
Frame Buffer 1GB x 2 512MB 512MB
Transistor Count 956M x 2 956M 956M
Manufacturing Process TSMC 55nm TSMC 55nm TSMC 55nm
Price Point $549 $299 $199


The benefit of single-card CrossFire is of course that you can use this single card on any platform, not just ones that explicitly support CF. Since CrossFire is supported on both Intel chipsets and AMD chipsets, it's a bit more flexible than SLI and the need for single-card CF isn't nearly as great as the need for single-card SLI.

Unlike most single-card multi-GPU solutions, the 4870 X2 is literally two Radeon HD 4870s on a single card. The clock speeds, both core and memory, are identical and this thing should perform like a pair of 4870s (which is pretty quick if you have forgotten). The only difference here is that while the standard Radeon HD 4870 ships with 512MB of GDDR5 memory, each RV770 on a X2 gets a full 1GB of GDDR5 for a total of 2GB per card.

...which leads us nicely into some of AMD's other products that will be coming out in the next month or so. There will be 1GB versions of both the Radeon HD 4870 and Radeon HD 4850.

Then at $399 we'll see a Radeon HD 4850 X2, which as you can probably guess is a pair of Radeon HD 4850 GPUs on a single card, but with 2GB of GDDR3 and not GDDR5 like the 4870 X2. As interesting as all of these cards are, we only have the 4870 X2 for you today, the rest will have to wait for another time. But it is worth noting that if you are interested in buying a Radeon HD 4870/4850 and keeping it for a while, you may want to wait for the 1GB versions as they should give you a bit more longevity.

Enough with being distracted by AMD's product lineup, let's talk about the competition.

Let's Talk Pricing


View All Comments

  • EglsFly - Tuesday, August 12, 2008 - link

    I agree!

    It is because of ATI/AMD's release of the 4000 series cards that Nvidia had to dramatically drop the price of its GPU's.

    AMD brought great performance to the masses at an affordable price point. Here they up the ante with an even higher performing solution and what do we get in return from Anandtech? A biased review full of negativity that it looks like it was written by somebody from Nvidia.
  • CyberHawk - Tuesday, August 12, 2008 - link

    That kind of message was I hoping for to get from review... a kind of didn't happen. Reply
  • BRDiger - Tuesday, August 12, 2008 - link

    I just wondered if you useed the 8.8 Catalysts... The testing rigs specs would be nice for comparison of the benchies... Reply
  • nubie - Wednesday, August 13, 2008 - link

    This is interesting, and thanks for the hints about a 1GB model, but guru3d ran an article two weeks ago on a 2GB 4850, so I believe that is trumped.

    I too was hoping for more enthusiasm, the 9800GTX is $200 and the just released GTX 260 is under $300?? Stop the presses nVidia is no longer on top!!

    AMD has wrested back the performance crown with a vengeance, and their mainstream products are totally playable in recent games.

    Meanwhile nVidia is trying to plug every price point with the 8800GS and 9600GSO and the 9600GT, not to mention the 9800GTX+, this is freaking ridiculous.

    You need to paint a more realistic picture, this is one of the rare times that mainstream games can be played for $170 while decimating the competition's products that cost $250, and the high end is owned by the same company with a working Dual chip card with the performance crown, and being a more efficient electricity user than the competition.

    If nVidia comes out with a GTX 260 x2 or a GTX 280 x2 I am going to look very carefully to see how glowing THAT review is.

    I want SLi and Crossfire to die. There is no reason to only allow 2 displays (or worse just one) on a multi-output machine. Worse still a machine with 2x PCI-E 16x slots (even in dual 8x mode) should be allowed to run any hardware that fits in them.

    This software hampering of a completely standard PCI-E interface is stupid and childish, they should just drop it.

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