GeForce 8800 GTS (G80) 320MB vs Radeon HD 4770

Intro

Compare those specifications to the Radeon HD 4770, which uses a 40 nm design. AMD has clocked the core speed at 750 MHz. The GDDR5 RAM is set to run at a speed of 800 MHz on this particular card. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
GeForce 8800 GTS (G80) 320MB		143 Watts
	Difference: 63 Watts (79%)

Memory Bandwidth

Theoretically speaking, the GeForce 8800 GTS (G80) 320MB will be 24% faster than the Radeon HD 4770 in general, due to its greater bandwidth. (explain)

GeForce 8800 GTS (G80) 320MB		63360 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 12160 (24%)

Texel Rate

The GeForce 8800 GTS (G80) 320MB is a bit (about 3%) more effective at AF than the Radeon HD 4770. (explain)

GeForce 8800 GTS (G80) 320MB		24624 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 624 (3%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4770 is a better choice, not by a very large margin though. (explain)

Radeon HD 4770		12000 Mpixels/sec
GeForce 8800 GTS (G80) 320MB		10260 Mpixels/sec
	Difference: 1740 (17%)

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 (measured in MB per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total number of texture units by the core 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 processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. 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 quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.