GeForce 8600 GT 512MB GDDR3 vs Radeon HD 6870

Intro

Compare all of that to the Radeon HD 6870, which comes with a clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It features 1120 SPUs, 56 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8600 GT 512MB GDDR3		47 Watts
Radeon HD 6870		151 Watts
	Difference: 104 Watts (221%)

Memory Bandwidth

The Radeon HD 6870 should in theory be a lot faster than the GeForce 8600 GT 512MB GDDR3 overall. (explain)

Radeon HD 6870		134400 MB/sec
GeForce 8600 GT 512MB GDDR3		22400 MB/sec
	Difference: 112000 (500%)

Texel Rate

The Radeon HD 6870 is much (more or less 483%) better at anisotropic filtering than the GeForce 8600 GT 512MB GDDR3. (explain)

Radeon HD 6870		50400 Mtexels/sec
GeForce 8600 GT 512MB GDDR3		8640 Mtexels/sec
	Difference: 41760 (483%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 6870 is the winner, and very much so. (explain)

Radeon HD 6870		28800 Mpixels/sec
GeForce 8600 GT 512MB GDDR3		4320 Mpixels/sec
	Difference: 24480 (567%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of information (measured in MB per second) that can be transported over the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher 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 amount of texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.