Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 5870
IntroThe Radeon HD 4850 1GB has core speeds of 625 MHz on the GPU, and 993 MHz on the 1024 MB of GDDR4 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 Rasterization Operator Units.
Compare all of that to the Radeon HD 5870, which has clock speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 memory. It features 1600(320x5) SPUs along with 80 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5870 will be 142% faster than the Radeon HD 4850 1GB overall, due to its greater data rate. (explain)
Texel RateThe Radeon HD 5870 will be a lot (approximately 172%) better at anisotropic filtering than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Radeon HD 5870 will be quite a bit (about 172%) faster with regards to FSAA than the Radeon HD 4850 1GB, and also 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 max amount of information (measured in MB per second) that can be moved over the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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.