GeForce 820M vs Radeon R9 M385X

Intro

Compare all that to the Radeon R9 M385X, which features GPU clock speed of 1100 MHz, and 4096 MB of GDDR5 RAM set to run at 1500 MHz through a 128-bit bus. It also is comprised of 896 SPUs, 56 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon R9 M385X will be 500% quicker than the GeForce 820M in general, because of its greater bandwidth. (explain)

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

Texel Rate

The Radeon R9 M385X is a lot (approximately 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, and very much so. (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: Bandwidth is the maximum amount of information (counted in MB per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the interface width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total number of texture units by the core 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 processed in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.