GeForce GT 420 vs Radeon HD 6770

Intro

Compare all of that to the Radeon HD 6770, which has GPU core speed of 900 MHz, and 512 MB of GDDR5 RAM running at 1050 MHz through a 128-bit bus. It also features 800 Stream Processors, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon HD 6770		108 Watts
	Difference: 58 Watts (116%)

Memory Bandwidth

The Radeon HD 6770, in theory, should perform much faster than the GeForce GT 420 overall. (explain)

Radeon HD 6770		67200 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 38400 (133%)

Texel Rate

The Radeon HD 6770 will be quite a bit (more or less 543%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

Radeon HD 6770		36000 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 30400 (543%)

Pixel Rate

The Radeon HD 6770 is much (more or less 414%) faster with regards to full screen anti-aliasing than the GeForce GT 420, and also able to handle higher resolutions better. (explain)

Radeon HD 6770		14400 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 11600 (414%)

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 (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 number of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total amount of texture units of the card 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 processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.