GeForce 8600 GTS vs GeForce GT 420

Intro

Compare those specs to the GeForce GT 420, which features a GPU core clock speed of 700 MHz, and 2048 MB of GDDR3 memory set to run at 900 MHz through a 128-bit bus. It also is made up of 48 Stream Processors, 8 TAUs, and 4 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
GeForce 8600 GTS		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

The GeForce 8600 GTS, in theory, should be just a bit faster than the GeForce GT 420 in general. (explain)

GeForce 8600 GTS		32000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 3200 (11%)

Texel Rate

The GeForce 8600 GTS is much (approximately 93%) more effective at texture filtering than the GeForce GT 420. (explain)

GeForce 8600 GTS		10800 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 5200 (93%)

Pixel Rate

The GeForce 8600 GTS is quite a bit (more or less 93%) more effective at anti-aliasing than the GeForce GT 420, and also should be able to handle higher screen resolutions without losing too much performance. (explain)

GeForce 8600 GTS		5400 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 2600 (93%)

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 data (measured in MB per second) that can be transported across the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 once 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 anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better this number, 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 card can possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.