Radeon HD 7870 vs Radeon R9 285

Intro

Compare those specifications to the Radeon R9 285, which uses a 28 nm design. AMD has clocked the core speed at 918 MHz. The GDDR5 memory is set to run at a speed of 1375 MHz on this particular model. It features 1792 SPUs along with 112 TAUs and 32 Rasterization Operator Units.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

Radeon R9 285		8500 points
Radeon HD 7870		6230 points
	Difference: 2270 (36%)

Ethereum Mining Hash Rate

Radeon R9 285		18 Mh/s
Radeon HD 7870		16 Mh/s
	Difference: 2 (13%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7870		175 Watts
Radeon R9 285		190 Watts
	Difference: 15 Watts (9%)

Memory Bandwidth

The Radeon R9 285 should in theory be a small bit faster than the Radeon HD 7870 in general. (explain)

Radeon R9 285		176000 MB/sec
Radeon HD 7870		153600 MB/sec
	Difference: 22400 (15%)

Texel Rate

The Radeon R9 285 will be much (more or less 29%) faster with regards to anisotropic filtering than the Radeon HD 7870. (explain)

Radeon R9 285		102816 Mtexels/sec
Radeon HD 7870		80000 Mtexels/sec
	Difference: 22816 (29%)

Pixel Rate

The Radeon HD 7870 is a little bit (about 9%) faster with regards to full screen anti-aliasing than the Radeon R9 285, and capable of handling higher screen resolutions without losing too much performance. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon R9 285		29376 Mpixels/sec
	Difference: 2624 (9%)

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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the largest amount of information (measured in MB per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.