GeForce 840M vs Radeon R9 M395X

Intro

Compare all of that to the Radeon R9 M395X, which features core speeds of 723 MHz on the GPU, and 1250 MHz on the 4096 MB of GDDR5 RAM. It features 2048 SPUs as well as 128 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 840M		30 Watts
Radeon R9 M395X		125 Watts
	Difference: 95 Watts (317%)

Memory Bandwidth

The Radeon R9 M395X should in theory be much faster than the GeForce 840M overall. (explain)

Radeon R9 M395X		160000 MB/sec
GeForce 840M		16000 MB/sec
	Difference: 144000 (900%)

Texel Rate

The Radeon R9 M395X will be quite a bit (more or less 275%) faster with regards to texture filtering than the GeForce 840M. (explain)

Radeon R9 M395X		92544 Mtexels/sec
GeForce 840M		24696 Mtexels/sec
	Difference: 67848 (275%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon R9 M395X is superior to the GeForce 840M, by far. (explain)

Radeon R9 M395X		23136 Mpixels/sec
GeForce 840M		8232 Mpixels/sec
	Difference: 14904 (181%)

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 max amount of data (measured in megabytes per second) that can be moved across the external memory interface in one second. It is calculated by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, 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, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.