GeForce GTX 870M vs Radeon R9 M395X

Intro

Compare all of that to the Radeon R9 M395X, which has GPU clock speed of 723 MHz, and 4096 MB of GDDR5 RAM set to run at 1250 MHz through a 256-bit bus. It also features 2048 Stream Processors, 128 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 870M		110 Watts
Radeon R9 M395X		125 Watts
	Difference: 15 Watts (14%)

Memory Bandwidth

The Radeon R9 M395X, in theory, should be a lot faster than the GeForce GTX 870M in general. (explain)

Radeon R9 M395X		160000 MB/sec
GeForce GTX 870M		96000 MB/sec
	Difference: 64000 (67%)

Texel Rate

The GeForce GTX 870M will be a bit (approximately 14%) more effective at AF than the Radeon R9 M395X. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon R9 M395X		92544 Mtexels/sec
	Difference: 12848 (14%)

Pixel Rate

The Radeon R9 M395X is a little bit (about 2%) better at AA than the GeForce GTX 870M, and will be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon R9 M395X		23136 Mpixels/sec
GeForce GTX 870M		22584 Mpixels/sec
	Difference: 552 (2%)

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 max amount of information (measured in megabytes per second) that can be moved across the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 are applied per second. This is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the clock 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 output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.