Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB uses a 55 nm design. AMD has set the core speed at 600 MHz. The DDR2 memory works at a speed of 500 MHz on this specific model. It features 320(64x5) SPUs along with 32 Texture Address Units and 8 Rasterization Operator Units.
Compare those specs to the Radeon HD 7750, which features a clock frequency of 800 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit memory bus, and makes use of a 28 nm design. It is made up of 512 SPUs, 32 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
The Radeon HD 7750 should theoretically be a lot faster than the Radeon HD 4650 512MB in general. (explain)
Texel RateThe Radeon HD 7750 is quite a bit (approximately 33%) better at anisotropic filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateThe Radeon HD 7750 will be quite a bit (more or less 167%) faster with regards to full screen anti-aliasing than the Radeon HD 4650 512MB, and also should be capable of handling higher screen 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.
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 (in units of MB per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. 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 anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.