GeForce GT 420 vs Geforce GTX 680

Intro

Compare those specifications to the Geforce GTX 680, which comes with core speeds of 1006 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 memory. It features 1536 SPUs along with 128 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Geforce GTX 680		195 Watts
	Difference: 145 Watts (290%)

Memory Bandwidth

Performance-wise, the Geforce GTX 680 should in theory be much superior to the GeForce GT 420 in general. (explain)

Geforce GTX 680		192256 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 163456 (568%)

Texel Rate

The Geforce GTX 680 will be much (approximately 2199%) better at AF than the GeForce GT 420. (explain)

Geforce GTX 680		128768 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 123168 (2199%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Geforce GTX 680 is superior to the GeForce GT 420, and very much so. (explain)

Geforce GTX 680		32192 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 29392 (1050%)

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: Bandwidth is the max amount of information (in units of megabytes per second) that can be transported across the external memory interface within a second. The number is calculated by multiplying the interface width by its memory speed. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.