Compare any two graphics cards:
GeForce GTS 450 vs Radeon HD 7770
IntroThe GeForce GTS 450 has clock speeds of 783 MHz on the GPU, and 902 MHz on the 512 MB of GDDR5 RAM. It features 192 SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.
Compare that to the Radeon HD 7770, which has a clock frequency of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It is made up of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7770 should in theory be quite a bit faster than the GeForce GTS 450 overall. (explain)
Texel RateThe Radeon HD 7770 is quite a bit (about 60%) better at texture filtering than the GeForce GTS 450. (explain)
Pixel RateThe Radeon HD 7770 should be a lot (about 28%) faster with regards to full screen anti-aliasing than the GeForce GTS 450, and also will be able to handle higher resolutions without losing too much performance. (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 max amount of data (in units of megabytes per second) that can be moved past the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the 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 maximum amount of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the card's 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 is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.