Radeon R9 M275X vs Radeon R9 M390X

Intro

Compare all that to the Radeon R9 M390X, which comes with a clock frequency of 723 MHz and a GDDR5 memory speed of 1250 MHz. It also features a 256-bit memory bus, and uses a 28 nm design. It is comprised of 2048 SPUs, 128 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon R9 M390X		125 Watts
	Difference: 75 Watts (150%)

Memory Bandwidth

Theoretically, the Radeon R9 M390X should perform quite a bit faster than the Radeon R9 M275X overall. (explain)

Radeon R9 M390X		160000 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 88000 (122%)

Texel Rate

The Radeon R9 M390X should be quite a bit (approximately 157%) faster with regards to AF than the Radeon R9 M275X. (explain)

Radeon R9 M390X		92544 Mtexels/sec
Radeon R9 M275X		36000 Mtexels/sec
	Difference: 56544 (157%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon R9 M390X is superior to the Radeon R9 M275X, by far. (explain)

Radeon R9 M390X		23136 Mpixels/sec
Radeon R9 M275X		14400 Mpixels/sec
	Difference: 8736 (61%)

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 information (in units of MB per second) that can be transferred past the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 amount of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

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