Radeon HD 3870 X2 512MB vs Radeon RX 580

Intro

Compare all that to the Radeon RX 580, which features GPU clock speed of 1257 MHz, and 8192 MB of GDDR5 memory running at 2000 MHz through a 256-bit bus. It also features 2304 Stream Processors, 144 TAUs, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon RX 580 should theoretically be much better than the Radeon HD 3870 X2 512MB overall. (explain)

Radeon RX 580		262144 MB/sec
Radeon HD 3870 X2 512MB		115200 MB/sec
	Difference: 146944 (128%)

Texel Rate

The Radeon RX 580 will be much (approximately 586%) better at texture filtering than the Radeon HD 3870 X2 512MB. (explain)

Radeon RX 580		181008 Mtexels/sec
Radeon HD 3870 X2 512MB		26400 Mtexels/sec
	Difference: 154608 (586%)

Pixel Rate

The Radeon RX 580 should be a lot (more or less 52%) better at anti-aliasing than the Radeon HD 3870 X2 512MB, and also will be capable of handling higher screen resolutions while still performing well. (explain)

Radeon RX 580		40224 Mpixels/sec
Radeon HD 3870 X2 512MB		26400 Mpixels/sec
	Difference: 13824 (52%)

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 one second. The number is worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better 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 amount of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock 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 applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units 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 output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.