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AMD Radeon HD 5670 Review - DX11 breaches the $100 mark

Manufacturer: AMD

DX11 continues to shrink

AMD Still Dominates DX11

It has nearly been five months since AMD first introduced its DX11-capable graphics cards starting with the AMD Radeon HD 5870 powerhouse that has been followed by the HD 5850, HD 5770 and HD 5750.  And even though there are very few titles available today (or even set for a Q1 launch) that will take advantage of DX11, you can be sure that NVIDIA and its investors are paying attention to how far behind the other GPU giant is falling.  With Fermi and GF100 (the consumer card design based on Fermi) set for a March release time frame, that would in theory give AMD a solid 6-7 month lead.  What they are able to do with that lead depends greatly on selling as many GPUs as possible between now and then to cement ATI's position as the leading GPU technology for the coming years. 

We have taken detailed looks at the Radeon 5000-series GPU in previous articles and explained how the architecture scales both UP and DOWN with cost and performance and size - a move that AMD has benefited from tremendously.  The new Radeon HD 5670 graphics card that we are reviewing today is a new silicon spin that shrinks die size quite a bit thus lowering costs to AMD and its partners in order to offer the first sub-$100 graphics card ever.

The RV830 GPU

As I mentioned above, the GPU on the Radeon HD 5670, known by its codename as RV830, is not just the GPU with some sections disable, but is instead a completely new 40nm GPU using fewer transistors and thus will be cheaper to build.  You can see the block diagram below:

This differs quite a bit from the original HD 5870 block diagram we showed you in September of 2009; RV830 consists of 5 SIMD engines with 80 stream processors per unit giving the GPU 400 total SPUs.  That is 1/4 the raw processing power of the full-sized HD 5870 card that has 1600 SPUs and should give you a relative comparison for performance right out of the gate.  The rest of the HD 5670 GPU includes 20 texture units and 32 ROP units and a 128-bit GDDR5 memory bus that can run at up to 64 GB/sec depend on the card vendor's implementation.


The transistor count of the HD 5670 is 627M - compare that to the 2.15B of the HD 5870 and you see why AMD would be saving so much more on the production of these chips as they are 3.4x smaller.  The clock speeds run at a respectable 775 MHz with more than 600 TeraFLOPS of raw computing power, a stat that AMD loves to throw around with their advantages in recent years.  AMD is also proud to have been able to bring GDDR5 memory speeds down to the sub-$99 price point (though NVIDIA did do it first with the GeForce GT 240 late in 2009) all for under 61w and thus not requiring any kind of external power connections. 

As we go over in detail in our HD 5870 review, there are some new
features that make the HD 5000-series of GPUs stand out from the

  • Support for DirectX 11 and Shader Model 5.0
  • Support for OpenCL 1.0 (and likely OpenCL 1.1)
  • Angle independent anisotropic filtering (finally!)
  • "Nearly free" 4xMSAA

  • Very low idle power consumption
  • AMD Eyefinity multi-monitor gaming - first performance testing here
  • Three monitor support on a single card

While the rest of the features are obviously an advantage even on $99 graphics cards, I am sure many of you will question the inclusion of Eyefinity support on a card with this type of computing horsepower.  AMD was steadfastly telling me that with a set of three 1600x900 displays an Eyefinity configuration was not only doable but impressive running some top games at well over 30 FPS.  I still see this as a niche feature for higher-end users in terms of gaming on multiple-displays but I still think the ability to connect three monitors to even a cheap GPU for general-purpose computing is a big advantage for AMD.

Radeon HD 5500 Series

Radeon HD 5400 Series

Though not available for our reviewing purposes today, AMD is also announcing the upcoming Radeon HD 5500 and 5400 series of cards that will bring features like Eyefinity and DX11 to even lower price points and lower power consumption levels.  The passively cooled HD 5400 should be an automatic consideration for an HTPC system and we are looking forward to playing with one next month.