GeForce GTX 850M vs Radeon HD 4870 512MB

Intro

Compare all of that to the Radeon HD 4870 512MB, which has core speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 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 4870 512MB		150 Watts
	Difference: 110 Watts (275%)

Memory Bandwidth

Theoretically, the Radeon HD 4870 512MB should perform much faster than the GeForce GTX 850M in general. (explain)

Radeon HD 4870 512MB		115200 MB/sec
GeForce GTX 850M		32000 MB/sec
	Difference: 83200 (260%)

Texel Rate

The GeForce GTX 850M should be a small bit (about 17%) more effective at AF than the Radeon HD 4870 512MB. (explain)

GeForce GTX 850M		35040 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 5040 (17%)

Pixel Rate

The GeForce GTX 850M will be a little bit (approximately 17%) better at AA than the Radeon HD 4870 512MB, and will be capable of handling higher screen resolutions more effectively. (explain)

GeForce GTX 850M		14016 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 2016 (17%)

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 transferred over the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, 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 figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called 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 reach the max fill rate.