GeForce GT 420 vs Radeon HD 3690/3830

Intro

Compare all that to the Radeon HD 3690/3830, which features a clock speed of 668 MHz and a GDDR3 memory frequency of 828 MHz. It also makes use of a 128-bit bus, and uses a 55 nm design. It is comprised of 320(64x5) SPUs, 16 TAUs, 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 be a little bit faster than the Radeon HD 3690/3830 overall. (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 much (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 a high screen resolution is important to you, then the Radeon HD 3690/3830 is the winner, by a large margin. (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: Bandwidth is the maximum amount of information (in units of MB per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster 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 processed in one second. This is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.