Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7870
IntroThe GeForce GTX 660 has a GPU clock speed of 980 MHz, and the 2048 MB of GDDR5 RAM runs at 1502 MHz through a 192-bit bus. It also is comprised of 960 SPUs, 80 Texture Address Units, and 24 ROPs.
Compare all that to the Radeon HD 7870, which comes with core clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 7870 should theoretically be a small bit superior to the GeForce GTX 660 overall. (explain)
Texel RateThe Radeon HD 7870 should be just a bit (approximately 2%) more effective at anisotropic filtering than the GeForce GTX 660. (explain)
Pixel RateThe Radeon HD 7870 will be quite a bit (more or less 36%) faster with regards to full screen anti-aliasing than the GeForce GTX 660, and also will be capable of handling higher resolutions better. (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 information (measured in megabytes per second) that can be transported across the external memory interface in a second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's 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 amount of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The better this number, 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 most pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.