Radeon HD 7870 vs Radeon R9 M385X

Intro

Compare all that to the Radeon R9 M385X, which comes with a clock frequency of 1100 MHz and a GDDR5 memory frequency of 1500 MHz. It also uses a 128-bit bus, and uses a 28 nm design. It features 896 SPUs, 56 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 7870 should be 60% faster than the Radeon R9 M385X in general, due to its higher bandwidth. (explain)

Radeon HD 7870		153600 MB/sec
Radeon R9 M385X		96000 MB/sec
	Difference: 57600 (60%)

Texel Rate

The Radeon HD 7870 will be a lot (approximately 30%) better at AF than the Radeon R9 M385X. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon R9 M385X		61600 Mtexels/sec
	Difference: 18400 (30%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 7870 is a better choice, by a large margin. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon R9 M385X		17600 Mpixels/sec
	Difference: 14400 (82%)

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 largest amount of information (measured in megabytes per second) that can be transported past the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

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