GeForce GT 420 vs GeForce GTX 950M

Intro

The GeForce GT 420 features a clock speed of 700 MHz and a GDDR3 memory speed of 900 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It is made up of 48 SPUs, 8 Texture Address Units, and 4 ROPs.

Compare that to the GeForce GTX 950M, which uses a 28 nm design. nVidia has set the core speed at 914 MHz. The DDR3 memory is set to run at a frequency of 1000 MHz on this particular card. It features 640 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of MB per second) that can be transported past the external memory interface in one second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.