GeForce 8800 GTX vs Radeon HD 7770

Intro

Compare all of that to the Radeon HD 7770, which comes with GPU core speed of 1000 MHz, and 1024 MB of GDDR5 memory set to run at 1125 MHz through a 128-bit bus. It also is comprised of 640 Stream Processors, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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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

Theoretically speaking, the GeForce 8800 GTX should be 20% faster than the Radeon HD 7770 in general, due to its higher data rate. (explain)

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

Texel Rate

The Radeon HD 7770 is just a bit (more or less 9%) better at anisotropic filtering 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 resolution is important to you, then the Radeon HD 7770 is the winner, but only just. (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: Memory bandwidth is the maximum amount of data (in units of MB per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units of the card 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 applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core speed of the card. 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 output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.