Compare any two graphics cards:
Radeon HD 4650 512MB vs Radeon HD 7750
IntroThe Radeon HD 4650 512MB makes use of a 55 nm design. AMD has set the core speed at 600 MHz. The DDR2 RAM runs at a speed of 500 MHz on this card. It features 320(64x5) SPUs as well as 32 TAUs and 8 ROPs.
Compare those specs to the Radeon HD 7750, which comes with GPU clock speed of 800 MHz, and 1024 MB of GDDR5 RAM set to run at 1125 MHz through a 128-bit bus. It also features 512 Stream Processors, 32 TAUs, and 16 ROPs.
Power Usage and Theoretical BenchmarksBoth cards have the same power consumption.
Theoretically speaking, the Radeon HD 7750 should be 350% faster than the Radeon HD 4650 512MB overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7750 should be much (more or less 33%) more effective at texture filtering than the Radeon HD 4650 512MB. (explain)
Pixel RateThe Radeon HD 7750 is a lot (more or less 167%) better at full screen anti-aliasing than the Radeon HD 4650 512MB, and will be capable of handling higher resolutions without losing too much performance. (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 maximum amount of data (counted in megabytes per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.