GeForce 8600 GT 512MB DDR2 vs Radeon HD 6990

Intro

Compare those specs to the Radeon HD 6990, which has core speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 RAM. It features 1536 SPUs as well as 96 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8600 GT 512MB DDR2		47 Watts
Radeon HD 6990		375 Watts
	Difference: 328 Watts (698%)

Memory Bandwidth

Performance-wise, the Radeon HD 6990 should in theory be quite a bit superior to the GeForce 8600 GT 512MB DDR2 overall. (explain)

Radeon HD 6990		320000 MB/sec
GeForce 8600 GT 512MB DDR2		12800 MB/sec
	Difference: 307200 (2400%)

Texel Rate

The Radeon HD 6990 will be a lot (about 1744%) faster with regards to texture filtering than the GeForce 8600 GT 512MB DDR2. (explain)

Radeon HD 6990		159360 Mtexels/sec
GeForce 8600 GT 512MB DDR2		8640 Mtexels/sec
	Difference: 150720 (1744%)

Pixel Rate

The Radeon HD 6990 will be quite a bit (approximately 1130%) faster with regards to FSAA than the GeForce 8600 GT 512MB DDR2, and should be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 6990		53120 Mpixels/sec
GeForce 8600 GT 512MB DDR2		4320 Mpixels/sec
	Difference: 48800 (1130%)

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 (counted in MB per second) that can be moved past the external memory interface in one second. It's calculated by multiplying the interface width by its memory speed. In the case of DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The figure 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 lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.