Radeon HD 4870 X2 vs Radeon R9 390X 8G

Intro

Compare those specs to the Radeon R9 390X 8G, which comes with a clock speed of 1050 MHz and a GDDR5 memory speed of 1500 MHz. It also makes use of a 512-bit bus, and makes use of a 28 nm design. It is made up of 2816 SPUs, 176 Texture Address Units, and 64 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 390X 8G		275 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 75 Watts (27%)

Memory Bandwidth

Performance-wise, the Radeon R9 390X 8G should theoretically be a lot superior to the Radeon HD 4870 X2 overall. (explain)

Radeon R9 390X 8G		384000 MB/sec
Radeon HD 4870 X2		230400 MB/sec
	Difference: 153600 (67%)

Texel Rate

The Radeon R9 390X 8G will be quite a bit (more or less 208%) faster with regards to texture filtering than the Radeon HD 4870 X2. (explain)

Radeon R9 390X 8G		184800 Mtexels/sec
Radeon HD 4870 X2		60000 Mtexels/sec
	Difference: 124800 (208%)

Pixel Rate

The Radeon R9 390X 8G is quite a bit (approximately 180%) faster with regards to AA than the Radeon HD 4870 X2, and also should be capable of handling higher screen resolutions while still performing well. (explain)

Radeon R9 390X 8G		67200 Mpixels/sec
Radeon HD 4870 X2		24000 Mpixels/sec
	Difference: 43200 (180%)

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 (counted in MB per second) that can be moved past the external memory interface in a second. It's worked out by multiplying the interface width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 amount of texture map elements (texels) that are applied in one second. This number is worked out 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill 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 reach the maximum fill rate.