GeForce GTX 275 vs Radeon R9 M390X

Intro

Compare those specs to the Radeon R9 M390X, which comes with core speeds of 723 MHz on the GPU, and 1250 MHz on the 4096 MB of GDDR5 RAM. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M390X		125 Watts
GeForce GTX 275		219 Watts
	Difference: 94 Watts (75%)

Memory Bandwidth

The Radeon R9 M390X should in theory be a lot faster than the GeForce GTX 275 in general. (explain)

Radeon R9 M390X		160000 MB/sec
GeForce GTX 275		127008 MB/sec
	Difference: 32992 (26%)

Texel Rate

The Radeon R9 M390X will be quite a bit (approximately 83%) faster with regards to texture filtering than the GeForce GTX 275. (explain)

Radeon R9 M390X		92544 Mtexels/sec
GeForce GTX 275		50640 Mtexels/sec
	Difference: 41904 (83%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon R9 M390X is the winner, and very much so. (explain)

Radeon R9 M390X		23136 Mpixels/sec
GeForce GTX 275		17724 Mpixels/sec
	Difference: 5412 (31%)

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 data (in units of megabytes per second) that can be transferred over the external memory interface in one second. The number is calculated by multiplying the interface width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total texture units 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 most pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core clock speed. 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 is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.