Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7750
IntroThe GeForce GT 640 DDR3 has a clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also features a 128-bit memory bus, and makes use of a 28 nm design. It is comprised of 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the Radeon HD 7750, which comes with GPU core speed of 800 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 512 SPUs, 32 TAUs, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7750 is 26% quicker than the GeForce GT 640 DDR3 overall, because of its higher data rate. (explain)
Texel RateThe GeForce GT 640 DDR3 should be a small bit (about 13%) more effective at texture filtering than the Radeon HD 7750. (explain)
Pixel RateIf using a high resolution is important to you, then the GeForce GT 640 DDR3 is a better choice, but it probably won't make a huge difference. (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 data (counted in megabytes per second) that can be transported across the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, 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 applied in one second. This number is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.