GeForce GTX 850M vs Radeon HD 3870 1GB

Intro

Compare those specs to the Radeon HD 3870 1GB, which comes with clock speeds of 775 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR4 RAM. 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)

GeForce GTX 850M		40 Watts
Radeon HD 3870 1GB		106 Watts
	Difference: 66 Watts (165%)

Memory Bandwidth

Performance-wise, the Radeon HD 3870 1GB should in theory be quite a bit better than the GeForce GTX 850M in general. (explain)

Radeon HD 3870 1GB		72000 MB/sec
GeForce GTX 850M		32000 MB/sec
	Difference: 40000 (125%)

Texel Rate

The GeForce GTX 850M should be a lot (more or less 183%) faster with regards to texture filtering than the Radeon HD 3870 1GB. (explain)

GeForce GTX 850M		35040 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 22640 (183%)

Pixel Rate

The GeForce GTX 850M will be a small bit (about 13%) more effective at full screen anti-aliasing than the Radeon HD 3870 1GB, and will be capable of handling higher resolutions better. (explain)

GeForce GTX 850M		14016 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 1616 (13%)

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 maximum amount of information (counted in megabytes per second) that can be moved across the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the card's 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 are processed per second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to 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 bandwidth is, the lower the ability to reach the max fill rate.