GeForce GT 420 vs Radeon HD 3690/3830

Intro

Compare those specs to the Radeon HD 3690/3830, which uses a 55 nm design. AMD has set the core speed at 668 MHz. The GDDR3 memory runs at a speed of 828 MHz on this specific card. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 3690/3830		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

Theoretically, the GeForce GT 420 should perform just a bit faster than the Radeon HD 3690/3830 in general. (explain)

GeForce GT 420		28800 MB/sec
Radeon HD 3690/3830		26496 MB/sec
	Difference: 2304 (9%)

Texel Rate

The Radeon HD 3690/3830 will be a lot (approximately 91%) faster with regards to AF than the GeForce GT 420. (explain)

Radeon HD 3690/3830		10688 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 5088 (91%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 3690/3830 is the winner, and very much so. (explain)

Radeon HD 3690/3830		10688 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 7888 (282%)

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 (counted in MB per second) that can be transported across the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range 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 amount of texture units by the core 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 in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the 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 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, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.