Compare any two graphics cards:
Radeon HD 3870 512MB vs Radeon HD 4830 1GB
IntroThe Radeon HD 3870 512MB makes use of a 55 nm design. AMD has clocked the core frequency at 775 MHz. The GDDR3 RAM runs at a frequency of 900 MHz on this specific model. It features 320(64x5) SPUs as well as 16 TAUs and 16 ROPs.
Compare all that to the Radeon HD 4830 1GB, which uses a 55 nm design. AMD has set the core frequency at 575 MHz. The GDDR4 memory runs at a frequency of 900 MHz on this particular model. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so theoretically they should perform the same. (explain)
Texel RateThe Radeon HD 4830 1GB should be a lot (about 48%) more effective at AF than the Radeon HD 3870 512MB. (explain)
Pixel RateThe Radeon HD 3870 512MB is quite a bit (approximately 35%) better at full screen anti-aliasing than the Radeon HD 4830 1GB, and capable of handling higher screen resolutions better. (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 (counted in megabytes per second) that can be transferred across the external memory interface within a second. It is calculated by multiplying the interface width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, 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 amount of texture map elements (texels) that are applied per second. This number is worked out by multiplying the total amount 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.