Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 7770
IntroThe Radeon HD 4850 1GB comes with a clock speed of 625 MHz and a GDDR4 memory speed of 993 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Compare all of that to the Radeon HD 7770, which has a clock speed of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit bus, and uses a 28 nm design. It is comprised of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7770 should be 13% faster than the Radeon HD 4850 1GB overall, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7770 is much (approximately 60%) more effective at texture filtering than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Radeon HD 7770 should be a lot (approximately 60%) faster with regards to FSAA than the Radeon HD 4850 1GB, and should be able to handle higher 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 MB 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. If the card has DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.