GeForce GTX 280 vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which comes with clock speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs along with 96 TAUs and 32 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 280		236 Watts
Radeon HD 6990		375 Watts
	Difference: 139 Watts (59%)

Memory Bandwidth

The Radeon HD 6990 should in theory be much faster than the GeForce GTX 280 overall. (explain)

Radeon HD 6990		320000 MB/sec
GeForce GTX 280		141696 MB/sec
	Difference: 178304 (126%)

Texel Rate

The Radeon HD 6990 is much (about 231%) more effective at AF than the GeForce GTX 280. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce GTX 280		48160 Mtexels/sec
	Difference: 111200 (231%)

Pixel Rate

The Radeon HD 6990 should be much (approximately 176%) faster with regards to FSAA than the GeForce GTX 280, and should be able to handle higher screen resolutions better. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce GTX 280		19264 Mpixels/sec
	Difference: 33856 (176%)

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: Memory bandwidth is the maximum amount of information (in units of megabytes per second) that can be transported past the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type memory, it must be multiplied by 2 once 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 anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock 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 one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.