Radeon R9 285 vs Radeon R9 M275X

Intro

Compare all that to the Radeon R9 M275X, which uses a 28 nm design. AMD has clocked the core speed at 900 MHz. The GDDR5 memory is set to run at a speed of 1125 MHz on this specific card. It features 640 SPUs along with 40 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

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

In theory, the Radeon R9 285 should be 144% quicker than the Radeon R9 M275X overall, because of its higher data rate. (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%) faster with regards to AF than the Radeon R9 M275X. (explain)

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

Pixel Rate

If using high levels of AA is important to you, then the Radeon R9 285 is a better choice, by a large margin. (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: Bandwidth is the maximum amount of information (in units of MB per second) that can be moved past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 once again. If 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 higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.