GeForce 840M vs Radeon R9 285

Intro

Compare those specs to the Radeon R9 285, which comes with clock speeds of 918 MHz on the GPU, and 1375 MHz on the 2048 MB of GDDR5 memory. It features 1792 SPUs along with 112 TAUs and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

Radeon R9 285		8500 points
GeForce 840M		1600 points
	Difference: 6900 (431%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 840M		30 Watts
Radeon R9 285		190 Watts
	Difference: 160 Watts (533%)

Memory Bandwidth

Theoretically speaking, the Radeon R9 285 should be much faster than the GeForce 840M in general. (explain)

Radeon R9 285		176000 MB/sec
GeForce 840M		16000 MB/sec
	Difference: 160000 (1000%)

Texel Rate

The Radeon R9 285 will be much (more or less 316%) more effective at texture filtering than the GeForce 840M. (explain)

Radeon R9 285		102816 Mtexels/sec
GeForce 840M		24696 Mtexels/sec
	Difference: 78120 (316%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon R9 285 is a better choice, by a large margin. (explain)

Radeon R9 285		29376 Mpixels/sec
GeForce 840M		8232 Mpixels/sec
	Difference: 21144 (257%)

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 data (measured in megabytes per second) that can be moved past the external memory interface within a second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total number 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of 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 number of Raster Operations Pipelines by the the core 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 output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.