GeForce 8800 GT 256MB vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which features GPU clock speed of 950 MHz, and 3072 MB of GDDR5 RAM running at 1500 MHz through a 384-bit bus. It also is made up of 2048 SPUs, 128 TAUs, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8800 GT 256MB		105 Watts
Radeon HD 7990		375 Watts
	Difference: 270 Watts (257%)

Memory Bandwidth

Theoretically, the Radeon HD 7990 should be much faster than the GeForce 8800 GT 256MB in general. (explain)

Radeon HD 7990		576000 MB/sec
GeForce 8800 GT 256MB		44800 MB/sec
	Difference: 531200 (1186%)

Texel Rate

The Radeon HD 7990 will be quite a bit (about 624%) faster with regards to texture filtering than the GeForce 8800 GT 256MB. (explain)

Radeon HD 7990		243200 Mtexels/sec
GeForce 8800 GT 256MB		33600 Mtexels/sec
	Difference: 209600 (624%)

Pixel Rate

The Radeon HD 7990 will be a lot (approximately 533%) better at full screen anti-aliasing than the GeForce 8800 GT 256MB, and also will be capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 7990		60800 Mpixels/sec
GeForce 8800 GT 256MB		9600 Mpixels/sec
	Difference: 51200 (533%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of information (counted in MB per second) that can be transported across the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, 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 are applied per second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.