Radeon R9 M275X vs Radeon R9 M280X

Intro

Compare those specs to the Radeon R9 M280X, which comes with a GPU core clock speed of 900 MHz, and 4096 MB of GDDR5 RAM running at 1375 MHz through a 128-bit bus. It also is comprised of 896 Stream Processors, 56 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon R9 M280X		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

In theory, the Radeon R9 M280X should be 22% faster than the Radeon R9 M275X overall, due to its higher data rate. (explain)

Radeon R9 M280X		88000 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 16000 (22%)

Texel Rate

The Radeon R9 M280X should be much (approximately 40%) better at anisotropic filtering than the Radeon R9 M275X. (explain)

Radeon R9 M280X		50400 Mtexels/sec
Radeon R9 M275X		36000 Mtexels/sec
	Difference: 14400 (40%)

Pixel Rate

Both cards have the exact same pixel fill rate, so in theory they should perform equally good at at anti-aliasing, and be capable of handling the same resolutions. (explain)

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 max amount of data (in units of megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 amount of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.