Radeon HD 4870 X2 vs Radeon R9 M270X

Intro

Compare those specifications to the Radeon R9 M270X, which features GPU core speed of 725 MHz, and 2048 MB of GDDR5 RAM set to run at 1125 MHz through a 128-bit bus. It also features 640 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 4870 X2 should theoretically be quite a bit better than the Radeon R9 M270X in general. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon R9 M270X		72000 MB/sec
	Difference: 158400 (220%)

Texel Rate

The Radeon HD 4870 X2 will be quite a bit (more or less 107%) better at texture filtering than the Radeon R9 M270X. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon R9 M270X		29000 Mtexels/sec
	Difference: 31000 (107%)

Pixel Rate

The Radeon HD 4870 X2 is quite a bit (more or less 107%) better at anti-aliasing than the Radeon R9 M270X, and able to handle higher resolutions while still performing well. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon R9 M270X		11600 Mpixels/sec
	Difference: 12400 (107%)

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 max amount of information (measured in megabytes per second) that can be transported across the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total amount of texture units of the card 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 processed in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs 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 rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.