GeForce GTX 850M vs Radeon HD 7870

Intro

The GeForce GTX 850M makes use of a 28 nm design. nVidia has clocked the core speed at 876 MHz. The DDR3 RAM is set to run at a frequency of 1000 MHz on this particular card. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Compare all of that to the Radeon HD 7870, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this specific model. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of data (counted in MB per second) that can be transferred over the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.