GeForce 940M vs GeForce GT 420

Intro

Compare those specifications to the GeForce GT 420, which comes with core clock speeds of 700 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR3 RAM. It features 48 SPUs along with 8 TAUs and 4 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The GeForce GT 420, in theory, should perform a lot faster than the GeForce 940M overall. (explain)

GeForce GT 420		28800 MB/sec
GeForce 940M		16000 MB/sec
	Difference: 12800 (80%)

Texel Rate

The GeForce 940M is quite a bit (more or less 359%) more effective at AF than the GeForce GT 420. (explain)

GeForce 940M		25728 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 20128 (359%)

Pixel Rate

The GeForce 940M will be much (approximately 206%) better at full screen anti-aliasing than the GeForce GT 420, and also should be capable of handling higher resolutions more effectively. (explain)

GeForce 940M		8576 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 5776 (206%)

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 largest amount of information (in units of megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it 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, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total number of texture units 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 a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number 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 fill rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.