Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 6950
IntroThe Radeon HD 5870 has a GPU core speed of 850 MHz, and the 1024 MB of GDDR5 memory runs at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) Stream Processors, 80 Texture Address Units, and 32 ROPs.
Compare those specs to the Radeon HD 6950, which comes with GPU clock speed of 800 MHz, and 1024 MB of GDDR5 memory running at 1250 MHz through a 256-bit bus. It also is comprised of 1408 Stream Processors, 88 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 should be 4% faster than the Radeon HD 5870 overall, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 6950 will be just a bit (more or less 4%) more effective at texture filtering than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 5870 should be a small bit (about 6%) more effective at FSAA than the Radeon HD 6950, and also will be able to handle higher screen resolutions more effectively. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Bandwidth is the largest amount of information (counted in MB per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.