GeForce 9800 GT 512MB vs GeForce GT 420

Intro

Compare those specifications to the GeForce GT 420, which comes with a clock frequency of 700 MHz and a GDDR3 memory frequency of 900 MHz. It also uses a 128-bit bus, and uses a 40 nm design. It features 48 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce 9800 GT 512MB		105 Watts
	Difference: 55 Watts (110%)

Memory Bandwidth

Theoretically speaking, the GeForce 9800 GT 512MB should be much faster than the GeForce GT 420 overall. (explain)

GeForce 9800 GT 512MB		57600 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 28800 (100%)

Texel Rate

The GeForce 9800 GT 512MB should be quite a bit (approximately 500%) better at texture filtering than the GeForce GT 420. (explain)

GeForce 9800 GT 512MB		33600 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 28000 (500%)

Pixel Rate

If using a high screen resolution is important to you, then the GeForce 9800 GT 512MB is superior to the GeForce GT 420, and very much so. (explain)

GeForce 9800 GT 512MB		9600 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 6800 (243%)

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 largest amount of information (counted in MB per second) that can be transferred past the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.