GeForce 9800 GX2 vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which has GPU clock speed of 830 MHz, and 2048 MB of GDDR5 RAM set to run at 1250 MHz through a 256-bit bus. It also is comprised of 1536 Stream Processors, 96 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 9800 GX2		197 Watts
Radeon HD 6990		375 Watts
	Difference: 178 Watts (90%)

Memory Bandwidth

Performance-wise, the Radeon HD 6990 should theoretically be a lot better than the GeForce 9800 GX2 overall. (explain)

Radeon HD 6990		320000 MB/sec
GeForce 9800 GX2		128000 MB/sec
	Difference: 192000 (150%)

Texel Rate

The Radeon HD 6990 will be quite a bit (more or less 108%) better at anisotropic filtering than the GeForce 9800 GX2. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce 9800 GX2		76800 Mtexels/sec
	Difference: 82560 (108%)

Pixel Rate

The Radeon HD 6990 will be quite a bit (about 177%) better at full screen anti-aliasing than the GeForce 9800 GX2, and also should be able to handle higher resolutions better. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 33920 (177%)

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 data (in units of MB per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, 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 is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to the 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 clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.