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 RAM works at a speed of 500 MHz on this particular card. It features 320(64x5) SPUs along with 32 Texture Address Units and 8 ROPs.
Compare all that to the Radeon HD 7750, which makes use of a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM is set to run at a speed of 1125 MHz on this particular card. It features 512 SPUs as well as 32 TAUs and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
In theory, 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 much (about 33%) better at AF than the Radeon HD 4650 512MB. (explain)
Pixel RateIf running with lots of anti-aliasing 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: Memory bandwidth is the largest amount of information (measured in MB per second) that can be transported over the external memory interface within a second. It is calculated by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, 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, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out 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 outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.