GeForce 825M vs GeForce 830M

Intro

Compare those specs to the GeForce 830M, which uses a 28 nm design. nVidia has clocked the core speed at 1029 MHz. The DDR3 RAM works at a speed of 900 MHz on this card. It features 256 SPUs as well as 16 TAUs and 8 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 830M		25 Watts
GeForce 825M		33 Watts
	Difference: 8 Watts (32%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should perform exactly the same. (explain)

Texel Rate

The GeForce 830M should be much (approximately 21%) more effective at AF than the GeForce 825M. (explain)

GeForce 830M		16464 Mtexels/sec
GeForce 825M		13600 Mtexels/sec
	Difference: 2864 (21%)

Pixel Rate

The GeForce 830M should be much (approximately 21%) more effective at anti-aliasing than the GeForce 825M, and should be capable of handling higher screen resolutions without losing too much performance. (explain)

GeForce 830M		8232 Mpixels/sec
GeForce 825M		6800 Mpixels/sec
	Difference: 1432 (21%)

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 (in units of MB per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 amount of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The better 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 could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.