Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 7850
IntroThe Radeon HD 4850 512MB uses a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR3 RAM runs at a speed of 993 MHz on this particular card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
Compare that to the Radeon HD 7850, which makes use of a 28 nm design. AMD has clocked the core speed at 860 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this particular card. It features 1024 SPUs along with 64 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 7850 is 142% faster than the Radeon HD 4850 512MB in general, due to its higher data rate. (explain)
Texel RateThe Radeon HD 7850 should be a lot (approximately 120%) more effective at texture filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 4850 512MB, 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: Bandwidth is the largest amount of information (counted in MB per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the interface width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better 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 amount of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.