GeForce 9800 GX2 vs Radeon HD 6850

Intro

Compare those specs to the Radeon HD 6850, which comes with core speeds of 775 MHz on the GPU, and 1000 MHz on the 1024 MB of GDDR5 memory. It features 960 SPUs along with 48 TAUs and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6850		127 Watts
GeForce 9800 GX2		197 Watts
	Difference: 70 Watts (55%)

Memory Bandwidth

Both cards have exactly the same memory bandwidth, so theoretically they should perform exactly the same. (explain)

Texel Rate

The GeForce 9800 GX2 should be quite a bit (about 106%) more effective at AF than the Radeon HD 6850. (explain)

GeForce 9800 GX2		76800 Mtexels/sec
Radeon HD 6850		37200 Mtexels/sec
	Difference: 39600 (106%)

Pixel Rate

The Radeon HD 6850 is a lot (about 29%) more effective at anti-aliasing than the GeForce 9800 GX2, and capable of handling higher resolutions without losing too much performance. (explain)

Radeon HD 6850		24800 Mpixels/sec
GeForce 9800 GX2		19200 Mpixels/sec
	Difference: 5600 (29%)

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 largest amount of data (measured in megabytes per second) that can be transferred across the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher 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 amount of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, 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 most pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.