GeForce 8800 GT 256MB vs GeForce GT 420

Intro

Compare that to the GeForce GT 420, which uses a 40 nm design. nVidia has clocked the core frequency at 700 MHz. The GDDR3 memory runs at a speed of 900 MHz on this specific card. It features 48 SPUs along with 8 Texture Address Units and 4 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce 8800 GT 256MB		105 Watts
	Difference: 55 Watts (110%)

Memory Bandwidth

In theory, the GeForce 8800 GT 256MB should be much faster than the GeForce GT 420 in general. (explain)

GeForce 8800 GT 256MB		44800 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 16000 (56%)

Texel Rate

The GeForce 8800 GT 256MB should be quite a bit (approximately 500%) more effective at texture filtering than the GeForce GT 420. (explain)

GeForce 8800 GT 256MB		33600 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 28000 (500%)

Pixel Rate

If running with high levels of AA is important to you, then the GeForce 8800 GT 256MB is a better choice, and very much so. (explain)

GeForce 8800 GT 256MB		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 max amount of information (measured in megabytes per second) that can be moved past the external memory interface within a second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once 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 amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per 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. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends 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.