GeForce 820M vs Radeon R9 M390X

Intro

Compare that to the Radeon R9 M390X, which features a core clock frequency of 723 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 256-bit memory bus, and makes use of a 28 nm design. It features 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
Radeon R9 M390X		125 Watts
	Difference: 110 Watts (733%)

Memory Bandwidth

Theoretically speaking, the Radeon R9 M390X should perform quite a bit faster than the GeForce 820M overall. (explain)

Radeon R9 M390X		160000 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 144000 (900%)

Texel Rate

The Radeon R9 M390X will be much (approximately 704%) faster with regards to anisotropic filtering than the GeForce 820M. (explain)

Radeon R9 M390X		92544 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 81040 (704%)

Pixel Rate

The Radeon R9 M390X will be a lot (approximately 704%) better at AA than the GeForce 820M, and also will be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon R9 M390X		23136 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 20260 (704%)

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 max amount of information (in units of megabytes per second) that can be transported past the external memory interface within a second. It is worked out 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 it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount 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 higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.