Compare any two graphics cards:
GeForce GTS 250 512MB vs Radeon HD 5770
IntroThe GeForce GTS 250 512MB features clock speeds of 738 MHz on the GPU, and 1100 MHz on the 512 MB of GDDR3 RAM. It features 128 SPUs as well as 64 Texture Address Units and 16 Rasterization Operator Units.
Compare all of that to the Radeon HD 5770, which features a GPU core clock speed of 850 MHz, and 1024 MB of GDDR5 memory running at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5770 is 9% faster than the GeForce GTS 250 512MB in general, because of its greater data rate. (explain)
Texel RateThe GeForce GTS 250 512MB should be a lot (about 39%) faster with regards to texture filtering than the Radeon HD 5770. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 5770 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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be transported across the external memory interface within a second. It is calculated by multiplying the interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, 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 number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling 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 chip can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core speed of the card. 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 is also dependant 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.