Compare any two graphics cards:
Radeon HD 5830 vs Radeon HD 6850
IntroThe Radeon HD 5830 uses a 40 nm design. AMD has clocked the core frequency at 800 MHz. The GDDR5 RAM works at a frequency of 1000 MHz on this specific card. It features 1120(224x5) SPUs as well as 56 TAUs and 16 Rasterization Operator Units.
Compare all of that to the Radeon HD 6850, which comes with clock speeds of 775 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 RAM. It features 960 SPUs along with 48 TAUs and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe Radeon HD 5830 should be a small bit (more or less 20%) better at texture filtering than the Radeon HD 6850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6850 is superior to the Radeon HD 5830, 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: Bandwidth is the maximum amount of information (in units of MB per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure 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 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 maximum amount of pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel 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 maximum fill rate.