GeForce GT 420 vs Radeon HD 3690/3830

Intro

Compare those specs to the Radeon HD 3690/3830, which comes with a core clock speed of 668 MHz and a GDDR3 memory frequency of 828 MHz. It also features a 128-bit memory bus, and uses a 55 nm design. It features 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 3690/3830		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

The GeForce GT 420, in theory, should perform just a 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 a lot (about 91%) more effective at 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

The Radeon HD 3690/3830 is much (more or less 282%) faster with regards to FSAA than the GeForce GT 420, and also capable of handling higher resolutions better. (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 information (measured in MB per second) that can be transported past the external memory interface in a second. The number is worked out by multiplying the interface width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount 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 fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.