GeForce 8800 GTX vs Radeon HD 7770

Intro

Compare those specs to the Radeon HD 7770, which has core clock speeds of 1000 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
GeForce 8800 GTX		155 Watts
	Difference: 75 Watts (94%)

Memory Bandwidth

In theory, the GeForce 8800 GTX should perform a little bit faster than the Radeon HD 7770 in general. (explain)

GeForce 8800 GTX		86400 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 14400 (20%)

Texel Rate

The Radeon HD 7770 will be a small bit (about 9%) more effective at AF than the GeForce 8800 GTX. (explain)

Radeon HD 7770		40000 Mtexels/sec
GeForce 8800 GTX		36800 Mtexels/sec
	Difference: 3200 (9%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 7770 is the winner, but it probably won't make a huge difference. (explain)

Radeon HD 7770		16000 Mpixels/sec
GeForce 8800 GTX		13800 Mpixels/sec
	Difference: 2200 (16%)

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 information (counted in megabytes per second) that can be moved over the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The better 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 the video card can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number 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 also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.