GeForce GT 420 vs Radeon HD 3870 1GB

Intro

Compare all of that to the Radeon HD 3870 1GB, which comes with GPU core speed of 775 MHz, and 1024 MB of GDDR4 RAM set to run at 1125 MHz through a 256-bit bus. It also is comprised of 320(64x5) SPUs, 16 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 3870 1GB		106 Watts
	Difference: 56 Watts (112%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 3870 1GB will be 150% faster than the GeForce GT 420 overall, due to its higher bandwidth. (explain)

Radeon HD 3870 1GB		72000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 43200 (150%)

Texel Rate

The Radeon HD 3870 1GB is much (approximately 121%) better at AF than the GeForce GT 420. (explain)

Radeon HD 3870 1GB		12400 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 6800 (121%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 3870 1GB is superior to the GeForce GT 420, by far. (explain)

Radeon HD 3870 1GB		12400 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 9600 (343%)

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 (counted in MB per second) that can be transported past the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory speed. In the case of DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.