GeForce GTX 870M vs Radeon HD 4870 X2

Intro

Compare all of that to the Radeon HD 4870 X2, which comes with a core clock frequency of 750 MHz and a GDDR5 memory speed of 900 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It features 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

In theory, the Radeon HD 4870 X2 should be quite a bit faster than the GeForce GTX 870M in general. (explain)

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

Texel Rate

The GeForce GTX 870M will be much (approximately 76%) faster with regards to texture filtering 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 using high levels of AA is important to you, then the Radeon HD 4870 X2 is superior to the GeForce GTX 870M, though only just barely. (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: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be moved across the external memory interface in a second. It is worked out by multiplying the bus width by its memory speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the 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 number of texture map elements (texels) that are processed per second. This number is worked out by multiplying the total texture units of the card 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 processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units 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 quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.