GeForce 8800 GTS (G80) 640MB vs Radeon HD 7770

Intro

Compare those specifications to the Radeon HD 7770, which uses a 28 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 memory is set to run at a frequency of 1125 MHz on this model. It features 640 SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
GeForce 8800 GTS (G80) 640MB		143 Watts
	Difference: 63 Watts (79%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 7770 will be 14% faster than the GeForce 8800 GTS (G80) 640MB in general, because of its higher data rate. (explain)

Radeon HD 7770		72000 MB/sec
GeForce 8800 GTS (G80) 640MB		63360 MB/sec
	Difference: 8640 (14%)

Texel Rate

The Radeon HD 7770 will be a lot (about 62%) more effective at texture filtering than the GeForce 8800 GTS (G80) 640MB. (explain)

Radeon HD 7770		40000 Mtexels/sec
GeForce 8800 GTS (G80) 640MB		24624 Mtexels/sec
	Difference: 15376 (62%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 7770 is superior to the GeForce 8800 GTS (G80) 640MB, and very much so. (explain)

Radeon HD 7770		16000 Mpixels/sec
GeForce 8800 GTS (G80) 640MB		10260 Mpixels/sec
	Difference: 5740 (56%)

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 (counted in megabytes per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better 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 amount of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can 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 card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.