GeForce 8400 GS 512MB vs Radeon HD 6770 1GB

Intro

Compare that to the Radeon HD 6770 1GB, which comes with GPU clock speed of 900 MHz, and 1024 MB of GDDR5 RAM running at 1050 MHz through a 128-bit bus. It also is made up of 800 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8400 GS 512MB		40 Watts
Radeon HD 6770 1GB		108 Watts
	Difference: 68 Watts (170%)

Memory Bandwidth

In theory, the Radeon HD 6770 1GB is 950% quicker than the GeForce 8400 GS 512MB overall, due to its greater bandwidth. (explain)

Radeon HD 6770 1GB		67200 MB/sec
GeForce 8400 GS 512MB		6400 MB/sec
	Difference: 60800 (950%)

Texel Rate

The Radeon HD 6770 1GB is much (approximately 592%) better at AF than the GeForce 8400 GS 512MB. (explain)

Radeon HD 6770 1GB		36000 Mtexels/sec
GeForce 8400 GS 512MB		5200 Mtexels/sec
	Difference: 30800 (592%)

Pixel Rate

The Radeon HD 6770 1GB will be a lot (approximately 454%) better at AA than the GeForce 8400 GS 512MB, and should be capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 6770 1GB		14400 Mpixels/sec
GeForce 8400 GS 512MB		2600 Mpixels/sec
	Difference: 11800 (454%)

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 largest amount of data (counted in MB per second) that can be transported over the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.