Compare any two graphics cards:
Radeon HD 7990 vs Radeon R9 290X
IntroThe Radeon HD 7990 has a core clock speed of 950 MHz and a GDDR5 memory speed of 1500 MHz. It also makes use of a 384-bit bus, and makes use of a 28 nm design. It features 2048 SPUs, 128 TAUs, and 32 ROPs.
Compare those specifications to the Radeon R9 290X, which features a core clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also features a 512-bit memory bus, and uses a 28 nm design. It features 2816 SPUs, 176 TAUs, and 64 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7990, in theory, should be much faster than the Radeon R9 290X in general. (explain)
Texel RateThe Radeon HD 7990 will be a lot (about 73%) faster with regards to AF than the Radeon R9 290X. (explain)
Pixel RateThe Radeon HD 7990 should be just a bit (approximately 19%) more effective at AA than the Radeon R9 290X, and able to handle 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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
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 (in units of megabytes per second) that can be moved over the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 number of texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends 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 max fill rate.