Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 6950
IntroThe Radeon HD 5870 comes with a GPU core clock 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 Raster Operation Units.
Compare those specs to the Radeon HD 6950, which has a clock speed of 800 MHz and a GDDR5 memory frequency of 1250 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1408 SPUs, 88 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6950 should perform a small bit faster than the Radeon HD 5870 in general. (explain)
Texel RateThe Radeon HD 6950 will be a bit (more or less 4%) better at AF than the Radeon HD 5870. (explain)
Pixel RateThe Radeon HD 5870 should be a bit (about 6%) more effective at full screen anti-aliasing than the Radeon HD 6950, and able to handle higher screen resolutions without losing too much performance. (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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be transferred over the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, 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 amount of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.