Radeon R9 390 8G vs Radeon R9 M275X

Intro

Compare all that to the Radeon R9 M275X, which comes with core clock speeds of 900 MHz on the GPU, and 1125 MHz on the 2048 MB of GDDR5 memory. It features 640 SPUs as well as 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon R9 390 8G		275 Watts
	Difference: 225 Watts (450%)

Memory Bandwidth

Performance-wise, the Radeon R9 390 8G should theoretically be much better than the Radeon R9 M275X in general. (explain)

Radeon R9 390 8G		384000 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 312000 (433%)

Texel Rate

The Radeon R9 390 8G should be much (more or less 344%) more effective at texture filtering than the Radeon R9 M275X. (explain)

Radeon R9 390 8G		160000 Mtexels/sec
Radeon R9 M275X		36000 Mtexels/sec
	Difference: 124000 (344%)

Pixel Rate

The Radeon R9 390 8G is quite a bit (approximately 344%) faster with regards to AA than the Radeon R9 M275X, and will be able to handle higher resolutions better. (explain)

Radeon R9 390 8G		64000 Mpixels/sec
Radeon R9 M275X		14400 Mpixels/sec
	Difference: 49600 (344%)

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 information (counted in MB per second) that can be transported over the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the 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 card can possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.