Radeon R9 M275X vs Radeon R9 M280X

Intro

Compare that to the Radeon R9 M280X, which features a clock frequency of 900 MHz and a GDDR5 memory speed of 1375 MHz. It also features a 128-bit memory bus, and uses a 28 nm design. It is made up of 896 SPUs, 56 Texture Address Units, 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

As far as performance goes, the Radeon R9 M280X should theoretically be a lot superior to the Radeon R9 M275X in general. (explain)

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

Texel Rate

The Radeon R9 M280X is quite a bit (about 40%) more effective at texture 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 exactly the same pixel rate, so in theory they should perform equally good at at FSAA, and be able to handle 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: Bandwidth is the maximum amount of information (counted in MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the video 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 most pixels that the graphics chip can possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs 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 output rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.