Radeon HD 4870 X2 vs Radeon RX 580

Intro

Compare all of that to the Radeon RX 580, which has clock speeds of 1257 MHz on the GPU, and 2000 MHz on the 8192 MB of GDDR5 RAM. It features 2304 SPUs as well as 144 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon RX 580		185 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 165 Watts (89%)

Memory Bandwidth

In theory, the Radeon RX 580 should perform a bit faster than the Radeon HD 4870 X2 overall. (explain)

Radeon RX 580		262144 MB/sec
Radeon HD 4870 X2		230400 MB/sec
	Difference: 31744 (14%)

Texel Rate

The Radeon RX 580 will be a lot (approximately 202%) faster with regards to anisotropic filtering than the Radeon HD 4870 X2. (explain)

Radeon RX 580		181008 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 121008 (202%)

Pixel Rate

The Radeon RX 580 should be quite a bit (approximately 68%) more effective at full screen anti-aliasing than the Radeon HD 4870 X2, and capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon RX 580		40224 Mpixels/sec
Radeon HD 4870 X2		24000 Mpixels/sec
	Difference: 16224 (68%)

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 (counted in MB per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.