Compare any two graphics cards:
Geforce GTX 690 vs Radeon HD 7990
IntroThe Geforce GTX 690 comes with a clock speed of 915 MHz and a GDDR5 memory frequency of 1502 MHz. It also makes use of a 256-bit bus, and makes use of a 28 nm design. It is made up of 1536 SPUs, 128 Texture Address Units, and 32 ROPs.
Compare that to the Radeon HD 7990, which uses a 28 nm design. AMD has set the core speed at 950 MHz. The GDDR5 RAM works at a frequency of 1500 MHz on this specific card. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7990 should perform a lot faster than the Geforce GTX 690 overall. (explain)
Texel RateThe Radeon HD 7990 is just a bit (approximately 4%) more effective at AF than the Geforce GTX 690. (explain)
Pixel RateThe Radeon HD 7990 is a little bit (about 4%) faster with regards to FSAA than the Geforce GTX 690, and also will be able to handle higher resolutions while still performing well. (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.
Geforce GTX 690
Radeon HD 7990
Memory Bandwidth: Bandwidth is the maximum amount of data (counted in MB per second) that can be moved past the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the 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 can be processed per second. This is worked out by multiplying the total amount of 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 applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units 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 output rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.
Geforce GTX 690
Radeon HD 7990