GeForce 8800 GT 256MB vs Radeon HD 4770

Intro

Compare all that to the Radeon HD 4770, which makes use of a 40 nm design. AMD has set the core frequency at 750 MHz. The GDDR5 RAM works at a frequency of 800 MHz on this particular card. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
GeForce 8800 GT 256MB		105 Watts
	Difference: 25 Watts (31%)

Memory Bandwidth

In theory, the Radeon HD 4770 should be a small bit faster than the GeForce 8800 GT 256MB in general. (explain)

Radeon HD 4770		51200 MB/sec
GeForce 8800 GT 256MB		44800 MB/sec
	Difference: 6400 (14%)

Texel Rate

The GeForce 8800 GT 256MB is quite a bit (about 40%) better at AF than the Radeon HD 4770. (explain)

GeForce 8800 GT 256MB		33600 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 9600 (40%)

Pixel Rate

The Radeon HD 4770 should be a lot (approximately 25%) better at full screen anti-aliasing than the GeForce 8800 GT 256MB, and also will be capable of handling higher resolutions more effectively. (explain)

Radeon HD 4770		12000 Mpixels/sec
GeForce 8800 GT 256MB		9600 Mpixels/sec
	Difference: 2400 (25%)

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 max amount of information (in units of megabytes per second) that can be moved over the external memory interface within a second. It's calculated by multiplying the card's interface width by its memory speed. If the card has DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 can be processed per second. This figure is calculated by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.