Radeon R9 M275X vs Radeon R9 M280X

Intro

Compare all of that to the Radeon R9 M280X, which comes with GPU clock speed of 900 MHz, and 4096 MB of GDDR5 memory running at 1375 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

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 in general, because of its greater data rate. (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 (approximately 40%) more effective 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 rate, so in theory they should perform equally good at at AA, and be capable of handling the same screen 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 largest amount of data (in units of megabytes per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. 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 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.