GeForce 840M vs Radeon R9 M265X

Intro

Compare all of that to the Radeon R9 M265X, which has core clock speeds of 575 MHz on the GPU, and 1125 MHz on the 2048 MB of GDDR5 memory. It features 640 SPUs as well as 40 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

As far as performance goes, the Radeon R9 M265X should theoretically be a lot superior to the GeForce 840M overall. (explain)

Radeon R9 M265X		72000 MB/sec
GeForce 840M		16000 MB/sec
	Difference: 56000 (350%)

Texel Rate

The GeForce 840M is just a bit (approximately 7%) better at AF than the Radeon R9 M265X. (explain)

GeForce 840M		24696 Mtexels/sec
Radeon R9 M265X		23000 Mtexels/sec
	Difference: 1696 (7%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon R9 M265X is the winner, not by a very large margin though. (explain)

Radeon R9 M265X		9200 Mpixels/sec
GeForce 840M		8232 Mpixels/sec
	Difference: 968 (12%)

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 largest amount of information (measured in MB per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the graphics 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 most pixels that the graphics card could 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 ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.