Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 6670 (OEM) 1GB
IntroThe GeForce GT 640 DDR3 makes use of a 28 nm design. nVidia has clocked the core frequency at 900 MHz. The DDR3 memory is set to run at a frequency of 1782 MHz on this particular card. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 6670 (OEM) 1GB, which has a clock frequency of 800 MHz and a GDDR5 memory frequency of 1000 MHz. It also uses a 128-bit bus, and makes use of a 40 nm design. It is made up of 480 SPUs, 24 Texture Address Units, and 8 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6670 (OEM) 1GB should theoretically perform just a bit faster than the GeForce GT 640 DDR3 overall. (explain)
Texel RateThe GeForce GT 640 DDR3 is much (more or less 50%) more effective at AF than the Radeon HD 6670 (OEM) 1GB. (explain)
Pixel RateThe GeForce GT 640 DDR3 is much (more or less 125%) better at AA than the Radeon HD 6670 (OEM) 1GB, and also will be capable of handling higher screen 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: Bandwidth is the maximum amount of information (measured in MB per second) that can be transported over the external memory interface in one second. It's calculated by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The better 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 a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.