GeForce GTX 870M vs Radeon HD 4870 X2

Intro

Compare that to the Radeon HD 4870 X2, which features a core clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 870M		110 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 240 Watts (218%)

Memory Bandwidth

Theoretically, the Radeon HD 4870 X2 should be a lot faster than the GeForce GTX 870M overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
GeForce GTX 870M		96000 MB/sec
	Difference: 134400 (140%)

Texel Rate

The GeForce GTX 870M is a lot (more or less 76%) better at AF than the Radeon HD 4870 X2. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 45392 (76%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 4870 X2 is superior to the GeForce GTX 870M, not by a very large margin though. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
GeForce GTX 870M		22584 Mpixels/sec
	Difference: 1416 (6%)

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 maximum amount of information (counted in MB per second) that can be transferred past the external memory interface in one second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, 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 that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.