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

Intro

Compare all that to the Radeon HD 7770, which uses a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory runs at a frequency of 1125 MHz on this model. It features 640 SPUs along with 40 Texture Address Units and 16 ROPs.

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

In theory, the Radeon HD 7770 should be a small bit faster than the GeForce 8800 GTS (G80) 640MB overall. (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 high levels of AA is important to you, then the Radeon HD 7770 is a better choice, by a large margin. (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 maximum amount of data (measured in megabytes per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 most pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.