Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB comes with a core clock frequency of 600 MHz and a DDR2 memory speed of 500 MHz. It also makes use of a 128-bit memory bus, and makes use of a 55 nm design. It is made up of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Compare those specs to the Radeon HD 7750, which uses a 28 nm design. AMD has clocked the core speed at 800 MHz. The GDDR5 RAM works at a speed of 1125 MHz on this card. It features 512 SPUs along with 32 TAUs and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
As far as performance goes, the Radeon HD 7750 should in theory be quite a bit better than the Radeon HD 4650 512MB overall. (explain)
Texel RateThe Radeon HD 7750 is a lot (more or less 33%) better at texture filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 7750 is the winner, and very much so. (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 (counted in megabytes per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, 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 that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.