GeForce 820M vs GeForce 8500 GT

Intro

Compare those specs to the GeForce 8500 GT, which uses a 80 nm design. nVidia has set the core speed at 450 MHz. The DDR2 RAM is set to run at a frequency of 400 MHz on this particular model. It features 16 SPUs as well as 8 Texture Address Units and 4 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce 8500 GT		45 Watts
	Difference: 30 Watts (200%)

Memory Bandwidth

As far as performance goes, the GeForce 820M should theoretically be a lot superior to the GeForce 8500 GT overall. (explain)

GeForce 820M		16000 MB/sec
GeForce 8500 GT		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The GeForce 820M is a lot (about 220%) more effective at AF than the GeForce 8500 GT. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8500 GT		3600 Mtexels/sec
	Difference: 7904 (220%)

Pixel Rate

The GeForce 820M should be much (about 60%) faster with regards to AA than the GeForce 8500 GT, and should be able to handle higher screen resolutions without slowing down too much. (explain)

GeForce 820M		2876 Mpixels/sec
GeForce 8500 GT		1800 Mpixels/sec
	Difference: 1076 (60%)

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 information (counted in MB per second) that can be transported over the external memory interface in one second. The number is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, 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 are applied in one second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the core 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 quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.