GeForce 8800 GTS (G80) 640MB vs GeForce GT 420

Intro

Compare those specs to the GeForce GT 420, which uses a 40 nm design. nVidia has set the core frequency at 700 MHz. The GDDR3 RAM runs at a frequency of 900 MHz on this particular card. It features 48 SPUs along with 8 TAUs and 4 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 93 Watts (186%)

Memory Bandwidth

Performance-wise, the GeForce 8800 GTS (G80) 640MB should theoretically be quite a bit better than the GeForce GT 420 in general. (explain)

GeForce 8800 GTS (G80) 640MB		63360 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 34560 (120%)

Texel Rate

The GeForce 8800 GTS (G80) 640MB is much (more or less 340%) faster with regards to texture filtering than the GeForce GT 420. (explain)

GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 19024 (340%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce 8800 GTS (G80) 640MB is the winner, by far. (explain)

GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 7460 (266%)

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 data (measured in MB per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range 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 is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling 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 could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.