Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 5870
IntroThe Radeon HD 5770 features a clock frequency of 850 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 5870, which features GPU clock speed of 850 MHz, and 1024 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also features 1600(320x5) SPUs, 80 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5870 should be a lot faster than the Radeon HD 5770 overall. (explain)
Texel RateThe Radeon HD 5870 should be quite a bit (approximately 100%) better at anisotropic filtering than the Radeon HD 5770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 5870 is superior to the Radeon HD 5770, by a large margin. (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 maximum amount of data (counted in megabytes per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the graphics 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 the video card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka 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, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.