GeForce GT 420 vs Geforce GTX 680

Intro

Compare that to the Geforce GTX 680, which makes use of a 28 nm design. nVidia has clocked the core speed at 1006 MHz. The GDDR5 RAM is set to run at a frequency of 1502 MHz on this specific model. It features 1536 SPUs as well as 128 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

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

Theoretically speaking, the Geforce GTX 680 is 568% faster than the GeForce GT 420 in general, because of its greater data rate. (explain)

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

Texel Rate

The Geforce GTX 680 should be a lot (approximately 2199%) faster with regards to anisotropic filtering 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 a high resolution is important to you, then the Geforce GTX 680 is the winner, by a large margin. (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: Memory bandwidth is the max amount of information (measured in megabytes per second) that can be transported over the external memory interface in one second. It is calculated by multiplying the interface width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total 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 processed in one second.

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