Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7990
IntroThe GeForce GT 640 DDR3 uses a 28 nm design. nVidia has set the core frequency at 900 MHz. The DDR3 RAM works at a speed of 1782 MHz on this specific card. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7990, which uses 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 particular card. It features 2048 SPUs as well as 128 TAUs and 32 Rasterization Operator Units.
BenchmarksThese are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.
3DMark Fire Strike Graphics Score
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7990 should be 910% quicker than the GeForce GT 640 DDR3 in general, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 7990 is quite a bit (about 744%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)
Pixel RateThe Radeon HD 7990 is much (more or less 322%) faster with regards to full screen anti-aliasing than the GeForce GT 640 DDR3, and will be able to handle higher resolutions more effectively. (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 GT 640 DDR3
Radeon HD 7990
Memory Bandwidth: Bandwidth is the maximum amount of data (measured in MB per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the card's bus width by its memory speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster 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 can be applied per second. This number is worked out 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 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 number of pixels the video card can possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output 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 get to the max fill rate.
GeForce GT 640 DDR3
Radeon HD 7990