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 clocked the core speed at 750 MHz. The GDDR5 memory is set to run at a speed of 900 MHz on this specific card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.
Compare those specifications to the Radeon HD 7850, which uses a 28 nm design. AMD has clocked the core frequency at 860 MHz. The GDDR5 RAM is set to run at a speed of 1200 MHz on this particular model. 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 is 33% quicker than the Radeon HD 4870 512MB overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7850 should be a lot (approximately 83%) better at texture 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 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 max amount of information (measured in megabytes per second) that can be transported over the external memory interface within a second. It is worked out by multiplying the interface width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, 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 can 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 ROPs by the clock 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 is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.