Radeon HD 7870 vs Radeon R9 270

Intro

The Radeon HD 7870 comes with a GPU core clock speed of 1000 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1200 MHz through a 256-bit bus. It also is made up of 1280 SPUs, 80 Texture Address Units, and 32 ROPs.

Compare all that to the Radeon R9 270, which makes use of a 28 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 RAM runs at a frequency of 1400 MHz on this specific card. It features 1280 SPUs along with 80 TAUs and 32 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be moved past the external memory interface in one second. The number is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the 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 are processed in one 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 applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the clock 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 rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.