GeForce 8800 GS vs GeForce GT 420

Intro

Compare all of that to the GeForce GT 420, which features a clock frequency of 700 MHz and a GDDR3 memory frequency of 900 MHz. It also makes use of a 128-bit memory bus, and uses a 40 nm design. It features 48 SPUs, 8 TAUs, and 4 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

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

Memory Bandwidth

The GeForce 8800 GS should in theory be a lot faster than the GeForce GT 420 overall. (explain)

GeForce 8800 GS		38400 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 9600 (33%)

Texel Rate

The GeForce 8800 GS will be quite a bit (about 371%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

GeForce 8800 GS		26400 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 20800 (371%)

Pixel Rate

The GeForce 8800 GS is quite a bit (about 136%) better at full screen anti-aliasing than the GeForce GT 420, and able to handle higher screen resolutions while still performing well. (explain)

GeForce 8800 GS		6600 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 3800 (136%)

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 largest amount of information (counted in megabytes per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the 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 number of pixels that the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.