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ATi Radeon HD 3850 in the test: Another price-performance hit?

ATi Radeon HD 3850 in the test: Another price-performance hit?

Overclockability

For many people out there, the newly bought graphics card won't be fast enough. Hardware is an effective means of satisfying this need for even more speedto overclock. As a small stability test, we ran 3DMark06, which is particularly graphics-heavy, and then tested the highest clock rate with the help of Company of Heroes, F.E.A.R and Prey. However, before taking measurements, you have to note that the results cannot be transferred to every card of the same type, as the quality differs from chip to chip.

Overclocking
  • Company of Heroes:
    • Radeon HD 3850 - Overclocked (750/855)
      61.8
    • Radeon HD 3850 - standard (668/828)
      59,3
  • FEAR:
    • Radeon HD 3850 - Overclocked (750/855)
      57.0
    • Radeon HD 3850 - Standard (668/828)
      53.0
  • Prey:
    • Radeon HD 3850 - Overclocked (750/855)
      52,1
    • Radeon HD 3850 - Standard (668/828)
      48,6

The RV670 GPU on the ATi Radeon HD 3850 still had some leeway for higher clock frequencies on our copy. Only at 750 MHz, which corresponds to a plus of 80 MHz, did the first crashes appear in a 3D application. On the other hand, the built-in memory was a stumbling block, which caused problems after a plus of more than 27 MHz and did not allow the 3DMark06 to finish properly. The maximum possible frequency was thus 855 MHz.

Apparently the memory is also the general stumbling block of the Radeon HD 3850 , because the performance improvements are not as high as one might assume based on the higher GPU clock. In our case, the graphics card is memory bandwidth limited. More thanWe couldn't get a plus of eight percent out of the Radeon HD 3850. Depending on the application, the speed only increased by four percent.

VC-1/H.264 playback

A few years ago, all PCs were faced with the then complicated task of to decode a DVD-Video. After the CPU had to work alone at first, and it was often overwhelmed by it, the graphics chip specialists came into fashion to equip their 3D accelerators with special functions in order to relieve the processor of the main work of decoding. A nice side effect was that the graphics cards could work with special algorithms that could improve the image quality without a great deal of performance. DVDs are no longer a challenge. A modern PC is now facing much more difficult tasks: decoding HD videos in the VC-1 or H.264 codec that have been recorded on a Blu-ray or an HD DVD (HD trailers have the same codecs as well as an identical image quality, but these are not encrypted, which is why the CPU load is a lot lower). We decided to film “Children of Men” on an HD DVD (1024p, 24 frames per second), which is available in the VC-1 codec on an HD DVD. We measure the CPU load every second in the first two and a half minutes of the film and show every fifth second in a progress diagram. The action film 'X-Men 3', which is available in H.264 format (1024p, 24 frames per second), must serve as a representative of the Blu-ray group. We clocked the CPU down to 1.86 GHz for the measurements.

VC-1 playback
Unit: Percent
  • Maximum:
    • ATi Radeon HD 3870
      48
    • ATi Radeon HD 3850
      46
    • Nvidia GeForce 8800 GT
      44
  • Average:
    • Nvidia GeForce 8800 GT
      31
    • ATi Radeon HD 3850
      24
    • ATi Radeon HD 3870
      22
  • Minimal:
    • ATi Radeon HD 3870
      9
    • ATi Radeon HD 3850
      8
    • Nvidia GeForce 8800 GT
      5

Neither the VC-1 nor the H.264 playback afforded the Radeon HD 3850 or any other test candidate a slip-up. Like the Radeon HD 3870, the Radeon HD 3850 can accelerate all HD video codecs and also has no difficulties in applying HDCP copy protection with a dual-link resolution such as 2560x1600. The same applies to the GeForce 8800 GT, but the VC-1 acceleration is not as high as that of the ATi cards. That is why we see the Radeon HD 3800 cards in front of a GeForce 8800 GT in VC-1 acceleration, while there is virtually a tie with the H.264 codec. There is no noticeable difference between the Radeon HD 3850 and the Radeon HD 3870 when it comes to the acceleration of HD videos.

H.264 playback
Unit: Percent
  • Maximum:
    • Nvidia GeForce 8800 GT
      52
    • ATi Radeon HD 3850
      33
  • Average:
    • Nvidia GeForce 8800 GT
      23
    • ATi Radeon HD3850
      20
  • Minimal:
    • Nvidia GeForce 8800 GT
      15
    • ATi Radeon HD 3850
      12

On the next page: Price-performance ratio

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