Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 5870
IntroThe Radeon HD 4850 1GB has a GPU clock speed of 625 MHz, and the 1024 MB of GDDR4 RAM is set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare all that to the Radeon HD 5870, which uses a 40 nm design. AMD has set the core frequency at 850 MHz. The GDDR5 memory runs at a speed of 1200 MHz on this model. It features 1600(320x5) SPUs along with 80 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5870 is 142% quicker than the Radeon HD 4850 1GB overall, because of its greater data rate. (explain)
Texel RateThe Radeon HD 5870 is a lot (more or less 172%) faster with regards to AF than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Radeon HD 5870 is a lot (about 172%) better at full screen anti-aliasing than the Radeon HD 4850 1GB, and also will be capable of handling higher screen resolutions while still performing well. (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 moved past the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video 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 record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number 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 filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.