GeForce 840M vs Radeon R9 M265X

Intro

Compare all of that to the Radeon R9 M265X, which has a clock speed of 575 MHz and a GDDR5 memory frequency of 1125 MHz. It also uses a 128-bit memory bus, and uses a 28 nm design. It is made up of 640 SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon R9 M265X should in theory perform a lot faster than the GeForce 840M overall. (explain)

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

Texel Rate

The GeForce 840M will be a bit (about 7%) more effective 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 a high screen resolution is important to you, then the Radeon R9 M265X is the winner, but it probably won't make a huge difference. (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 max amount of data (counted in MB 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 speed. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster 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 number of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.