GeForce GTX 850M vs Radeon HD 4870 X2

Intro

Compare those specs to the Radeon HD 4870 X2, which comes with a core clock frequency of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 850M		40 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 310 Watts (775%)

Memory Bandwidth

The Radeon HD 4870 X2 should theoretically perform a lot faster than the GeForce GTX 850M in general. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 850M		32000 MB/sec
	Difference: 198400 (620%)

Texel Rate

The Radeon HD 4870 X2 will be quite a bit (approximately 71%) more effective at texture filtering than the GeForce GTX 850M. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
GeForce GTX 850M		35040 Mtexels/sec
	Difference: 24960 (71%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon HD 4870 X2 is a better choice, by far. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce GTX 850M		14016 Mpixels/sec
	Difference: 9984 (71%)

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: Bandwidth is the max amount of data (measured in MB per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are 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 graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.