Conclusion

Our tests of the ASUS HD 6870 DirectCU graphics card show that the old ATI/AMD architecture, which traces its origin back to the R600 core (Radeon HD 2900) and uses the VLIW5 design for stream processors, has not exhausted its potential and can challenge the new Cayman architecture which features VLIW4 stream processors.

When clocked at a GPU frequency of about 1 GHz, the Radeon HD 6870 can deliver the same performance as the Radeon HD 6950 although AMD positions the latter into a higher price category. Moreover, our overclocked Radeon HD 6870 could compete with the GeForce GTX 560 Ti. You can see this in the summary diagrams:

At the resolution of 1600x900 pixels our Radeon HD 6870 overclocked to a GPU frequency of 1030 MHz and a memory frequency of 1265 (5060) MHz wins seven out of 18 tests in its struggle with the Radeon HD 6950. The score against the GeForce GTX 560 Ti is 6 to 12 but the gap is only large in Fermi-optimized or tessellation-heavy games such as Lost Planet 2, H.A.W.X. 2 and Unigine Heaven. Perhaps BattleForge can also be added here. Otherwise, the gap is no larger than 10%.

It is the resolution of 1920x1080 pixels that is the most relevant today. The overclocked ASUS card wins 8 and loses 10 tests against the Radeon HD 6950. Unigine Heaven is the only test where the ASUS HD 6870 DirectCU is downright slow, so it seems to be a better buy. Compared to the GeForce GTX 560 Ti, the ASUS wins 11 and loses 7 tests, falling behind the opponent the most in the same tests as at 1600x1200. So, if you are choosing between an ASUS HD 6870 DirectCU you intend to overclock and a regular GeForce GTX 560 Ti, you should consider not only the price factor but also what games you play. The ASUS won’t be a good choice for Lost Planet 2, for example.

Oddly enough, it is at 2560x1600 that the overclocked ASUS HD 6870 DirectCU enjoys the best score against the GeForce GTX 560 Ti: 11 wins, 6 losses and 1 draw. This must be largely due to the overclocked memory which has a peak bandwidth of 162 GBps whereas the reference GeForce GTX 560 Ti has a peak memory bandwidth of 128 GBps. It’s different with the Radeon HD 6950: the ASUS card can outperform it in only five out of 18 tests and by a very small margin at that. As usual, a lot of games are not really playable at that resolution. You can only enjoy a comfortable frame rate in Battlefield: Bad Company 2, Call of Duty: Black Ops, Fallout: New Vegas, Mass Effect 2 and F1 2010. Considering the price category the ASUS card belongs to, this is good performance, but you may want to prefer faster solutions to play at a 30-inch monitor.

ASUS HD 6870 DirectCU Summary

All in all, the ASUS HD 6870 DirectCU is an appealing version of Radeon HD 6870. Its 15MHz factory overclocking looks odd and cannot give you anything in terms of performance, but our sample could be easily overclocked to over 1 GHz for the GPU and over 5 GHz for the memory. At these frequencies it could challenge the GeForce GTX 560 Ti as well as Radeon HD 6950. We can additionally note the high quality of manufacture and components and the DirectCU cooler which ensures high cooling performance at low noise. The ASUS HD 6870 DirectCU won’t irritate you with its noise even when overclocked.

Thus, if your goal is to find an overclocker-friendly Radeon HD 6870, the ASUS HD 6870 DirectCU is quite a good option. There are only two things that may be a problem: the GPU voltage tweaking feature may not work properly and the price of the product may be too high. And while you can do without the former, the latter fact may make it more advisable to buy a Radeon HD 6950 or GeForce GTX 560 Ti which overclock well, too. When overclocked, these solutions will leave no chance to any Radeon HD 6870.

Highs:

• Superb quality of manufacture;
• May compete against GeForce GTX 560 Ti and Radeon HD 6950 in overclocked mode;
• Wide range of supported FSAA modes;
• Best quality of anisotropic filtering in the industry;
• Supports up to 6 monitors;
• Fully-fledged hardware HD video decoding, including DivX and 3D;
• High-quality HD video post-processing with scalability;
• Integrated sound core with HD support;
• Sound over HDMI;
• HDMI 1.4a;
• DisplayPort 1.2;
• Highly efficient cooling system;
• Low noise;
• Good overclocking potential.

Lows:

• Bigger size compared with the reference design;
• Higher power consumption;
• Low energy-efficiency in power-saving modes;
• Non-operational option to increase vGPU (could be the issue with our particular sample);
• Supports less GPGPU-accelerated software than the competitors;
• High price.