Compare any two graphics cards:
Radeon HD 4870 1GB vs Radeon HD 6670 (OEM)
IntroThe Radeon HD 4870 1GB comes with a clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also makes use of a 256-bit memory bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 6670 (OEM), which has GPU clock speed of 800 MHz, and 512 MB of GDDR5 RAM set to run at 1000 MHz through a 128-bit bus. It also is made up of 480 SPUs, 24 Texture Address Units, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 4870 1GB should perform a lot faster than the Radeon HD 6670 (OEM) overall. (explain)
Texel RateThe Radeon HD 4870 1GB is much (about 56%) better at anisotropic filtering than the Radeon HD 6670 (OEM). (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 4870 1GB 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: Bandwidth is the maximum amount of data (in units of megabytes per second) that can be moved over the external memory interface in a second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.