Radeon HD 7990 vs Radeon R9 M395X

Intro

Compare all that to the Radeon R9 M395X, which makes use of a 28 nm design. AMD has clocked the core speed at 723 MHz. The GDDR5 RAM works at a speed of 1250 MHz on this specific model. It features 2048 SPUs as well as 128 Texture Address Units and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M395X		125 Watts
Radeon HD 7990		375 Watts
	Difference: 250 Watts (200%)

Memory Bandwidth

The Radeon HD 7990 should theoretically be quite a bit faster than the Radeon R9 M395X in general. (explain)

Radeon HD 7990		576000 MB/sec
Radeon R9 M395X		160000 MB/sec
	Difference: 416000 (260%)

Texel Rate

The Radeon HD 7990 will be much (about 163%) better at AF than the Radeon R9 M395X. (explain)

Radeon HD 7990		243200 Mtexels/sec
Radeon R9 M395X		92544 Mtexels/sec
	Difference: 150656 (163%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 7990 is superior to the Radeon R9 M395X, by a large margin. (explain)

Radeon HD 7990		60800 Mpixels/sec
Radeon R9 M395X		23136 Mpixels/sec
	Difference: 37664 (163%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (counted in megabytes per second) that can be transported over the external memory interface within a second. It's calculated by multiplying the card's bus width by its memory speed. If it uses DDR memory, the result should be multiplied by 2 again. If it uses 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 amount of texture map elements (texels) that are processed in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.