Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 6670 (OEM) 1GB
IntroThe GeForce GT 640 DDR3 has core clock speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs along with 32 Texture Address Units and 16 ROPs.
Compare those specs to the Radeon HD 6670 (OEM) 1GB, which makes use of a 40 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory works at a frequency of 1000 MHz on this model. It features 480 SPUs as well as 24 TAUs and 8 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6670 (OEM) 1GB should perform a little bit faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 is much (approximately 50%) faster with regards to AF than the Radeon HD 6670 (OEM) 1GB. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is a better choice, 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: Memory bandwidth is the max amount of data (measured in MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This is calculated by multiplying the total texture units of the card 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 per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.