Compare any two graphics cards:
Radeon HD 3870 512MB vs Radeon HD 6670 (OEM) 1GB
IntroThe Radeon HD 3870 512MB uses a 55 nm design. AMD has set the core speed at 775 MHz. The GDDR3 memory runs at a speed of 900 MHz on this particular card. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 ROPs.
Compare those specifications to the Radeon HD 6670 (OEM) 1GB, which comes with a clock speed of 800 MHz and a GDDR5 memory frequency of 1000 MHz. It also features a 128-bit bus, and makes use of a 40 nm design. It is comprised of 480 SPUs, 24 Texture Address Units, and 8 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6670 (OEM) 1GB should theoretically be a small bit superior to the Radeon HD 3870 512MB overall. (explain)
Texel RateThe Radeon HD 6670 (OEM) 1GB is much (more or less 55%) better at texture filtering than the Radeon HD 3870 512MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 3870 512MB 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: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, 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 anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated 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 drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.