GeForce 820M vs Radeon R9 M385X

Intro

Compare all that to the Radeon R9 M385X, which has GPU clock speed of 1100 MHz, and 4096 MB of GDDR5 memory running at 1500 MHz through a 128-bit bus. It also features 896 Stream Processors, 56 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon R9 M385X should be 500% faster than the GeForce 820M overall, due to its higher data rate. (explain)

Radeon R9 M385X		96000 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 80000 (500%)

Texel Rate

The Radeon R9 M385X should be a lot (about 435%) more effective at texture filtering than the GeForce 820M. (explain)

Radeon R9 M385X		61600 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 50096 (435%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon R9 M385X is a better choice, by far. (explain)

Radeon R9 M385X		17600 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 14724 (512%)

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 megabytes per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum 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 clock speed of the chip. The higher 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 graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure 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 filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.