GeForce 820M vs GeForce 825M

Intro

Compare those specs to the GeForce 825M, which has GPU core speed of 850 MHz, and 2048 MB of DDR3 RAM set to run at 900 MHz through a 64-bit bus. It also is comprised of 384 Stream Processors, 16 Texture Address Units, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce 825M		33 Watts
	Difference: 18 Watts (120%)

Memory Bandwidth

Theoretically speaking, the GeForce 820M should perform just a bit faster than the GeForce 825M in general. (explain)

GeForce 820M		16000 MB/sec
GeForce 825M		14400 MB/sec
	Difference: 1600 (11%)

Texel Rate

The GeForce 825M is a small bit (approximately 18%) faster with regards to anisotropic filtering than the GeForce 820M. (explain)

GeForce 825M		13600 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 2096 (18%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce 825M is superior to the GeForce 820M, and very much so. (explain)

GeForce 825M		6800 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 3924 (136%)

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 (in units of megabytes per second) that can be transported past the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This is worked out 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 card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

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