Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB comes with a clock speed of 600 MHz and a DDR2 memory frequency of 500 MHz. It also uses a 128-bit bus, and makes use of a 55 nm design. It features 320(64x5) SPUs, 32 Texture Address Units, and 8 Raster Operation Units.
Compare all that to the Radeon HD 7750, which comes with clock speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 512 SPUs as well as 32 Texture Address Units and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 7750 should be quite a bit faster than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 7750 will be a lot (more or less 33%) faster with regards to texture filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7750 is superior to the Radeon HD 4650 512MB, by a large margin. (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.
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 (measured in MB per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one 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 this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video 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 Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.