Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7750
IntroThe GeForce GT 640 DDR3 features core speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare that to the Radeon HD 7750, which comes with a clock frequency of 800 MHz and a GDDR5 memory frequency of 1125 MHz. It also makes use of a 128-bit bus, and makes use of a 28 nm design. It is comprised of 512 SPUs, 32 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7750 will be 26% quicker than the GeForce GT 640 DDR3 in general, because of its higher data rate. (explain)
Texel RateThe GeForce GT 640 DDR3 is a small bit (more or less 13%) better at AF than the Radeon HD 7750. (explain)
Pixel RateIf running with a high resolution is important to you, then the GeForce GT 640 DDR3 is superior to the Radeon HD 7750, but not 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: Bandwidth is the maximum amount of information (in units of MB per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the 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 amount of texture map elements (texels) that are processed per second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher this number, the better the 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 number of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.