Radeon R9 285 vs Radeon R9 M275X

Intro

Compare those specs to the Radeon R9 M275X, which features a core clock speed of 900 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit memory bus, and makes use of a 28 nm design. It is made up of 640 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon R9 285		190 Watts
	Difference: 140 Watts (280%)

Memory Bandwidth

As far as performance goes, the Radeon R9 285 should in theory be quite a bit better than the Radeon R9 M275X overall. (explain)

Radeon R9 285		176000 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 104000 (144%)

Texel Rate

The Radeon R9 285 is a lot (approximately 186%) better at AF than the Radeon R9 M275X. (explain)

Radeon R9 285		102816 Mtexels/sec
Radeon R9 M275X		36000 Mtexels/sec
	Difference: 66816 (186%)

Pixel Rate

The Radeon R9 285 should be a lot (more or less 104%) faster with regards to FSAA than the Radeon R9 M275X, and should be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon R9 285		29376 Mpixels/sec
Radeon R9 M275X		14400 Mpixels/sec
	Difference: 14976 (104%)

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: Memory bandwidth is the maximum amount of information (measured in megabytes per second) that can be moved over the external memory interface in a second. The number is worked out by multiplying the bus width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total texture units 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 the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.