GeForce GT 420 vs Radeon HD 4870 512MB

Intro

Compare those specs to the Radeon HD 4870 512MB, which comes with a GPU core clock speed of 750 MHz, and 512 MB of GDDR5 memory set to run at 900 MHz through a 256-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 100 Watts (200%)

Memory Bandwidth

Theoretically, the Radeon HD 4870 512MB should perform quite a bit faster than the GeForce GT 420 in general. (explain)

Radeon HD 4870 512MB		115200 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 86400 (300%)

Texel Rate

The Radeon HD 4870 512MB is much (about 436%) better at anisotropic filtering than the GeForce GT 420. (explain)

Radeon HD 4870 512MB		30000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 24400 (436%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4870 512MB is a better choice, by far. (explain)

Radeon HD 4870 512MB		12000 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 9200 (329%)

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 moved past the external memory interface within a second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core 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 also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.