GeForce GTX 870M vs Radeon HD 3870 512MB

Intro

Compare those specifications to the Radeon HD 3870 512MB, which features clock speeds of 775 MHz on the GPU, and 900 MHz on the 512 MB of GDDR3 memory. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 512MB		106 Watts
GeForce GTX 870M		110 Watts
	Difference: 4 Watts (4%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 870M will be 67% quicker than the Radeon HD 3870 512MB in general, due to its higher data rate. (explain)

GeForce GTX 870M		96000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 38400 (67%)

Texel Rate

The GeForce GTX 870M should be quite a bit (about 750%) faster with regards to anisotropic filtering than the Radeon HD 3870 512MB. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 92992 (750%)

Pixel Rate

If using a high resolution is important to you, then the GeForce GTX 870M is the winner, by far. (explain)

GeForce GTX 870M		22584 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 10184 (82%)

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: Bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number 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 graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.