Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7950
IntroThe Radeon HD 5870 comes with a GPU core speed of 850 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1600(320x5) SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7950, which comes with GPU core speed of 800 MHz, and 1536 MB of GDDR5 RAM running at 1250 MHz through a 384-bit bus. It also features 1792 Stream Processors, 112 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7950 should be 56% quicker than the Radeon HD 5870 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7950 is a lot (more or less 32%) better at anisotropic filtering than the Radeon HD 5870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 5870 is superior to the Radeon HD 7950, though only just barely. (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 max amount of data (counted in MB per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock 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 output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.