Compare any two graphics cards:
Radeon HD 7990 vs Radeon R9 290X
IntroThe Radeon HD 7990 makes use of a 28 nm design. AMD has clocked the core speed at 950 MHz. The GDDR5 memory is set to run at a speed of 1500 MHz on this card. It features 2048 SPUs as well as 128 TAUs and 32 ROPs.
Compare those specifications to the Radeon R9 290X, which makes use of a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this particular model. It features 2816 SPUs as well as 176 TAUs and 64 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7990 should in theory perform quite a bit faster than the Radeon R9 290X in general. (explain)
Texel RateThe Radeon HD 7990 should be quite a bit (about 73%) faster with regards to AF than the Radeon R9 290X. (explain)
Pixel RateThe Radeon HD 7990 should be a small bit (approximately 19%) more effective at full screen anti-aliasing than the Radeon R9 290X, and also will be capable of handling higher screen resolutions without slowing down too much. (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 (in units of megabytes per second) that can be transferred over the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.