Radeon HD 7870 vs Radeon HD 7950 3GB

Intro

The Radeon HD 7870 uses a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM runs at a speed of 1200 MHz on this particular model. It features 1280 SPUs along with 80 Texture Address Units and 32 Rasterization Operator Units.

Compare all of that to the Radeon HD 7950 3GB, which features a GPU core clock speed of 800 MHz, and 3072 MB of GDDR5 RAM set to run at 1250 MHz through a 384-bit bus. It also is comprised of 1792 Stream Processors, 112 Texture Address Units, and 32 Raster Operation Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output 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 max fill rate.