GeForce 820M vs Radeon R9 M270X

Intro

Compare all that to the Radeon R9 M270X, which makes use of a 28 nm design. AMD has set the core speed at 725 MHz. The GDDR5 RAM works at a speed of 1125 MHz on this particular model. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically, the Radeon R9 M270X should be much faster than the GeForce 820M overall. (explain)

Radeon R9 M270X		72000 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 56000 (350%)

Texel Rate

The Radeon R9 M270X should be much (approximately 152%) faster with regards to AF than the GeForce 820M. (explain)

Radeon R9 M270X		29000 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 17496 (152%)

Pixel Rate

The Radeon R9 M270X is a lot (more or less 303%) more effective at AA than the GeForce 820M, and also able to handle higher resolutions while still performing well. (explain)

Radeon R9 M270X		11600 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 8724 (303%)

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 data (measured in megabytes per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better 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 texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total number 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can 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 Render Output Units by the the core speed of the card. 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 fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.