GeForce 9800 GTX vs GeForce GT 420

Intro

Compare that to the GeForce GT 420, which uses a 40 nm design. nVidia has clocked the core speed at 700 MHz. The GDDR3 memory is set to run at a frequency 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 9800 GTX		140 Watts
	Difference: 90 Watts (180%)

Memory Bandwidth

In theory, the GeForce 9800 GTX should be 144% quicker than the GeForce GT 420 overall, due to its greater bandwidth. (explain)

GeForce 9800 GTX		70400 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 41600 (144%)

Texel Rate

The GeForce 9800 GTX should be a lot (more or less 671%) faster with regards to texture filtering than the GeForce GT 420. (explain)

GeForce 9800 GTX		43200 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 37600 (671%)

Pixel Rate

If using a high screen resolution is important to you, then the GeForce 9800 GTX is the winner, by far. (explain)

GeForce 9800 GTX		10800 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 8000 (286%)

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 data (measured in megabytes per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the bus width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could 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 Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.