Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 5850
IntroThe GeForce GT 640 DDR3 features a clock speed of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also makes use of a 128-bit memory bus, and uses a 28 nm design. It features 384 SPUs, 32 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 5850, which comes with a core clock frequency of 725 MHz and a GDDR5 memory frequency of 1000 MHz. It also uses a 256-bit memory bus, and uses a 40 nm design. It is comprised of 1440(288x5) SPUs, 72 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 5850 should theoretically perform quite a bit faster than the GeForce GT 640 DDR3 in general. (explain)
Texel RateThe Radeon HD 5850 will be quite a bit (more or less 81%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe Radeon HD 5850 will be much (more or less 61%) faster with regards to AA than the GeForce GT 640 DDR3, and should be able to handle higher screen resolutions without slowing down too much. (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 largest amount of data (in units of megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 texture map elements (texels) that can be processed per second. This figure is worked out 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 in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel 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 ability to reach the maximum fill rate.