Compare any two graphics cards:
Radeon HD 7990 vs Radeon R9 290X
IntroThe Radeon HD 7990 comes with a GPU clock speed of 950 MHz, and the 3072 MB of GDDR5 RAM runs at 1500 MHz through a 384-bit bus. It also is comprised of 2048 Stream Processors, 128 TAUs, and 32 Raster Operation Units.
Compare those specifications to the Radeon R9 290X, which has a core clock frequency of 800 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 512-bit memory bus, and uses a 28 nm design. It is made up of 2816 SPUs, 176 TAUs, and 64 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7990 is 80% quicker than the Radeon R9 290X in general, due to its higher data rate. (explain)
Texel RateThe Radeon HD 7990 should be a lot (approximately 73%) more effective at anisotropic filtering than the Radeon R9 290X. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7990 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.
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 maximum amount of information (counted in megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core 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 is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.