Radeon HD 5870 vs Radeon R9 285

Intro

Compare all that to the Radeon R9 285, which makes use of a 28 nm design. AMD has clocked the core frequency at 918 MHz. The GDDR5 memory is set to run at a frequency of 1375 MHz on this particular model. It features 1792 SPUs as well as 112 TAUs and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5870		188 Watts
Radeon R9 285		190 Watts
	Difference: 2 Watts (1%)

Memory Bandwidth

The Radeon R9 285, in theory, should perform a bit faster than the Radeon HD 5870 in general. (explain)

Radeon R9 285		176000 MB/sec
Radeon HD 5870		153600 MB/sec
	Difference: 22400 (15%)

Texel Rate

The Radeon R9 285 should be a lot (about 51%) better at texture filtering than the Radeon HD 5870. (explain)

Radeon R9 285		102816 Mtexels/sec
Radeon HD 5870		68000 Mtexels/sec
	Difference: 34816 (51%)

Pixel Rate

The Radeon R9 285 will be a small bit (more or less 8%) better at FSAA than the Radeon HD 5870, and will be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon R9 285		29376 Mpixels/sec
Radeon HD 5870		27200 Mpixels/sec
	Difference: 2176 (8%)

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 maximum amount of information (measured in MB per second) that can be transported across the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, 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 can be processed in one second. This is calculated by multiplying the total texture units by the core 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 per second.

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