Compare any two graphics cards:
Radeon HD 4870 512MB vs Radeon HD 7850
IntroThe Radeon HD 4870 512MB features core clock speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Compare that to the Radeon HD 7850, which makes use of a 28 nm design. AMD has set the core speed at 860 MHz. The GDDR5 RAM runs at a speed of 1200 MHz on this card. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 should perform a lot faster than the Radeon HD 4870 512MB overall. (explain)
Texel RateThe Radeon HD 7850 should be a lot (about 83%) faster with regards to texture filtering than the Radeon HD 4870 512MB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7850 is superior to the Radeon HD 4870 512MB, and very much so. (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 maximum amount of information (in units of MB per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.