GeForce GTX 280 vs Radeon HD 7990

Intro

Compare those specs to the Radeon HD 7990, which features GPU core speed of 950 MHz, and 3072 MB of GDDR5 RAM set to run at 1500 MHz through a 384-bit bus. It also is comprised of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 280		236 Watts
Radeon HD 7990		375 Watts
	Difference: 139 Watts (59%)

Memory Bandwidth

Performance-wise, the Radeon HD 7990 should in theory be a lot superior to the GeForce GTX 280 overall. (explain)

Radeon HD 7990		576000 MB/sec
GeForce GTX 280		141696 MB/sec
	Difference: 434304 (307%)

Texel Rate

The Radeon HD 7990 should be quite a bit (more or less 405%) better at texture filtering than the GeForce GTX 280. (explain)

Radeon HD 7990		243200 Mtexels/sec
GeForce GTX 280		48160 Mtexels/sec
	Difference: 195040 (405%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 7990 is the winner, and very much so. (explain)

Radeon HD 7990		60800 Mpixels/sec
GeForce GTX 280		19264 Mpixels/sec
	Difference: 41536 (216%)

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 largest amount of data (counted in MB per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the core speed of the card. 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 many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.