Compare any two graphics cards:
Radeon HD 3870 512MB vs Radeon HD 6670 (OEM) 1GB
IntroThe Radeon HD 3870 512MB has core speeds of 775 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 320(64x5) SPUs along with 16 TAUs and 16 ROPs.
Compare those specs to the Radeon HD 6670 (OEM) 1GB, which comes with core speeds of 800 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 480 SPUs as well as 24 Texture Address Units and 8 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6670 (OEM) 1GB should perform a bit faster than the Radeon HD 3870 512MB overall. (explain)
Texel RateThe Radeon HD 6670 (OEM) 1GB will be quite a bit (more or less 55%) better at AF than the Radeon HD 3870 512MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 3870 512MB is a better choice, 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: Memory bandwidth is the maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 are processed in one second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling 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 chip could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core 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 quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.