Compare any two graphics cards:
Radeon HD 4870 512MB vs Radeon HD 7850
IntroThe Radeon HD 4870 512MB uses a 55 nm design. AMD has set the core speed at 750 MHz. The GDDR5 memory runs at a speed of 900 MHz on this model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.
Compare all that to the Radeon HD 7850, which uses a 28 nm design. AMD has clocked the core speed at 860 MHz. The GDDR5 RAM works at a speed of 1200 MHz on this specific card. It features 1024 SPUs as well as 64 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7850 should perform quite a bit faster than the Radeon HD 4870 512MB overall. (explain)
Texel RateThe Radeon HD 7850 should be a lot (about 83%) better at anisotropic filtering than the Radeon HD 4870 512MB. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 7850 is the winner, by far. (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 MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the bus width by its memory clock speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. 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 number of texture map elements (texels) that are applied per second. This number is worked out 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.