Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 6670 (OEM) 1GB
IntroThe GeForce GT 640 DDR3 features a clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also uses a 128-bit bus, and makes use of a 28 nm design. It is made up of 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 6670 (OEM) 1GB, which comes with a core clock speed of 800 MHz and a GDDR5 memory speed of 1000 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It is made up of 480 SPUs, 24 Texture Address Units, and 8 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6670 (OEM) 1GB should be a little bit faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 will be a lot (about 50%) faster with regards to anisotropic filtering than the Radeon HD 6670 (OEM) 1GB. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GT 640 DDR3 is the winner, by a large margin. (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 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 the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 can be applied per second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends 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.