Radeon HD 6800 Series
ATI Technologies, which is now part of AMD, used to come up with ingenious ideas and concepts that were often ahead of their time (and not always for their own good). Can we say the same about the new Radeon HD 6 series as compared to its processor? Let’s try to make everything out.
At first sight, the new Barts-based solutions seem to be a step backwards if you compare them to their Radeon HD 5800 counterparts. The reduced number of ALUs and texture-mapping units and the lower fillrate parameters may lead an inexperienced user to this conclusion. After all, ordinary users are often prone to be allured by big numbers and the Barts is indeed simpler and smaller than the Cypress, for example in its die size and transistor count. Superficially, the Radeon HD 6800 only seems to have but one advantage over the previous series. Its clock rate is 900 MHz (we mean the top model) as compared to the Radeon HD 5870’s 850 MHz. Otherwise, the Barts is inferior to the Cypress in every other quantitative parameter!
Well, of course this superficial approach to evaluating the new series is incorrect. First off, modern GPU architectures are so complex that the way their shader processors are organized may have a much higher effect on the GPU’s performance than the sheer number of ALUs it has. Second, we should keep it in mind that the previous-generation Cypress processor was devised as a top-performance chip with acceptable manufacturing cost whereas the Barts is not the top of the Radeon HD 6000 line-up. It is targeted at the price range of $150-250. In other words, Barts-based products are meant to compete with Nvidia’s GF104-based cards (both in the current as well as prospective versions with 384 shader processors).
So, it’s just a matter of perspective. Instead of viewing the Barts as a step backwards compared to the Radeon HD 5800, we must consider it as a great leap forward over the Radeon HD 5700 and as a dangerous rival to the GeForce GTX 460. The Barts core is superior to the GF104 in every parameter while being apparently simpler and more economical. Besides, we mustn’t forget about the host of innovations the new GPU brings about (there are enough of them to justify the number 6 in the model name, we must admit). Even if we don’t delve deep into the details of the Radeon HD 6800 architecture but limit ourselves to the basic specs only, we can see that the new solutions from AMD look very well balanced. According to official comments by AMD, they promise to be as successful as the Radeon HD 4850 which set a new standard of performance in the $199 segment of DirectX 10 compatibles in its time. The Radeon HD 6850 and 6870 have every chance to do the same among DirectX 11 compatible cards, especially as they have the right recommended pricing: $179 and $239, respectively.
As noted above, the Radeon HD 6800 architecture is full of various innovations and improvements. We’ll tell you more about them in the next section.