GeForce 820M vs GeForce 8400 GS 512MB

Intro

Compare all that to the GeForce 8400 GS 512MB, which features a core clock speed of 650 MHz and a DDR2 memory frequency of 400 MHz. It also features a 64-bit bus, and uses a 80 nm design. It features 16 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce 8400 GS 512MB		40 Watts
	Difference: 25 Watts (167%)

Memory Bandwidth

Theoretically speaking, the GeForce 820M should be a lot faster than the GeForce 8400 GS 512MB overall. (explain)

GeForce 820M		16000 MB/sec
GeForce 8400 GS 512MB		6400 MB/sec
	Difference: 9600 (150%)

Texel Rate

The GeForce 820M is much (more or less 121%) faster with regards to texture filtering than the GeForce 8400 GS 512MB. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8400 GS 512MB		5200 Mtexels/sec
	Difference: 6304 (121%)

Pixel Rate

The GeForce 820M should be just a bit (about 11%) faster with regards to AA than the GeForce 8400 GS 512MB, and able to handle higher screen resolutions more effectively. (explain)

GeForce 820M		2876 Mpixels/sec
GeForce 8400 GS 512MB		2600 Mpixels/sec
	Difference: 276 (11%)

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 maximum amount of data (counted in MB per second) that can be moved past the external memory interface within a second. It's calculated by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, the result 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 anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at handling 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 could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.