Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB has a clock frequency of 600 MHz and a DDR2 memory speed of 500 MHz. It also makes use of a 128-bit bus, and uses a 55 nm design. It features 320(64x5) SPUs, 32 Texture Address Units, and 8 ROPs.
Compare those specifications to the Radeon HD 7750, which features core speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 memory. It features 512 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 7750 will be 350% quicker than the Radeon HD 4650 512MB in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7750 will be quite a bit (approximately 33%) faster with regards to AF than the Radeon HD 4650 512MB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7750 is a better choice, 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: Bandwidth is the max amount of data (counted in megabytes per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This number is worked out by multiplying the total amount of texture units by the core 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 applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record 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 filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.