GeForce GT 420 vs GeForce GTX 850M

Intro

Compare those specifications to the GeForce GTX 850M, which features clock speeds of 876 MHz on the GPU, and 1000 MHz on the 2048 MB of DDR3 memory. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 850M		40 Watts
GeForce GT 420		50 Watts
	Difference: 10 Watts (25%)

Memory Bandwidth

The GeForce GTX 850M, in theory, should be just a bit faster than the GeForce GT 420 in general. (explain)

GeForce GTX 850M		32000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 3200 (11%)

Texel Rate

The GeForce GTX 850M should be quite a bit (more or less 526%) faster with regards to texture filtering than the GeForce GT 420. (explain)

GeForce GTX 850M		35040 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 29440 (526%)

Pixel Rate

The GeForce GTX 850M will be a lot (approximately 401%) better at anti-aliasing than the GeForce GT 420, and capable of handling higher screen resolutions better. (explain)

GeForce GTX 850M		14016 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 11216 (401%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be transferred past the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, it 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 anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the 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 that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure 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 filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.