Compare any two graphics cards:
GeForce GT 450 (OEM) vs Radeon HD 7870
IntroThe GeForce GT 450 (OEM) uses a 40 nm design. nVidia has clocked the core frequency at 790 MHz. The GDDR5 memory works at a speed of 1000 MHz on this card. It features 144 SPUs as well as 24 Texture Address Units and 24 ROPs.
Compare those specs to the Radeon HD 7870, which comes with a core clock frequency of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 256-bit memory bus, and makes use of a 28 nm design. It is comprised of 1280 SPUs, 80 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7870 will be 60% faster than the GeForce GT 450 (OEM) overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7870 will be a lot (more or less 322%) better at AF than the GeForce GT 450 (OEM). (explain)
Pixel RateThe Radeon HD 7870 should be quite a bit (approximately 69%) better at full screen anti-aliasing than the GeForce GT 450 (OEM), and also will be able to handle higher screen 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: Memory bandwidth is the largest amount of data (measured in MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it should be multiplied by 2 once 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 AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total texture units of the card by the core 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 in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.