GeForce GTX 870M vs Radeon R9 M385X

Intro

Compare all of that to the Radeon R9 M385X, which has a GPU core clock speed of 1100 MHz, and 4096 MB of GDDR5 RAM set to run at 1500 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should have the same performance. (explain)

Texel Rate

The GeForce GTX 870M should be quite a bit (more or less 71%) more effective at anisotropic filtering than the Radeon R9 M385X. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon R9 M385X		61600 Mtexels/sec
	Difference: 43792 (71%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the GeForce GTX 870M is a better choice, and very much so. (explain)

GeForce GTX 870M		22584 Mpixels/sec
Radeon R9 M385X		17600 Mpixels/sec
	Difference: 4984 (28%)

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 MB per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once 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, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.