Compare any two graphics cards:
Radeon HD 3650 256MB vs Radeon HD 3690/3830
IntroThe Radeon HD 3650 256MB uses a 55 nm design. AMD has clocked the core frequency at 725 MHz. The DDR2 RAM is set to run at a speed of 800 MHz on this specific card. It features 120(24x5) SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.
Compare all that to the Radeon HD 3690/3830, which comes with clock speeds of 668 MHz on the GPU, and 828 MHz on the 256 MB of GDDR3 RAM. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 3690/3830 will be 4% quicker than the Radeon HD 3650 256MB in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 3690/3830 is much (approximately 84%) better at AF than the Radeon HD 3650 256MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 3690/3830 is superior to the Radeon HD 3650 256MB, 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 (in units of megabytes per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's 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 amount of texture map elements (texels) that can be applied in one 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.