The Sapphire Radeon HD 4670 GDDR4 model was a few frames per second faster than the GDDR3 model, but the difference was not too huge in that it the Radeon HD 4830 was still significantly faster. Though the Sapphire GDDR4 model should be selling for roughly the same as the GDDR3 model (if not, just a few dollars more), which is worth it for slightly better performance. Unfortunately, we were unable to overclock this graphics card due to an issue with the Catalyst Linux driver, but that should be worked out in the belated Catalyst 9.1 update. The GDDR4 memory operates at 1100MHz but there should be room for squeezing a few more Megahertz out of it. We previously overclocked the core on the GDDR3 version of HD 4670 quite well.
What is also significant about this graphics card is the larger cooler. This cooler is very quiet but it had done a great job at keeping the ATI GPU core cool and the memory is also cooled by heatsinks. If you are interested in a lower-end ATI graphics card that is economical, the Sapphire Radeon HD 4670 GDDR4 is a PCI Express 2.0 graphics card worth considering.
For those concerned about open-source support, AMD has released R700 3D register documentation and R700 3D code to begin supporting the Radeon HD 4000 family with open-source OpenGL acceleration on Linux. Coming as part of this work is also 2D EXA acceleration and X-Video support. The xf86-video-ati and xf86-video-radeonhd drivers have already had mode-setting support for the RV730 GPUs for quite a while already. The R700 3D support should evolve throughout this year and get really interesting once Gallium3D starts hitting Linux desktop distributions.
One unfortunate area about the R700 series support on Linux with the Catalyst driver is there still is no reliable video API that it supports for offloading decoding to the GPU. AMD has been working vigorously on XvBA, or X-Video Bitstream Acceleration, but it has yet to be released to the public. We hope, however, that the R700 XvBA support that uses the Unified Video Decoder 2 (UVD2) will be released in the Catalyst Linux driver in the near future.
For pricing information and more resources on ATI Radeon graphics cards, visit TestFreaks.com.