GeForce 820M vs GeForce 8600 GT 1GB GDDR3

Intro

Compare those specs to the GeForce 8600 GT 1GB GDDR3, which makes use of a 80 nm design. nVidia has clocked the core speed at 540 MHz. The GDDR3 memory is set to run at a frequency of 700 MHz on this specific model. It features 32 SPUs along with 16 Texture Address Units and 8 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce 8600 GT 1GB GDDR3		47 Watts
	Difference: 32 Watts (213%)

Memory Bandwidth

Theoretically, the GeForce 8600 GT 1GB GDDR3 should perform much faster than the GeForce 820M overall. (explain)

GeForce 8600 GT 1GB GDDR3		22400 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 6400 (40%)

Texel Rate

The GeForce 820M will be much (more or less 33%) better at AF than the GeForce 8600 GT 1GB GDDR3. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8600 GT 1GB GDDR3		8640 Mtexels/sec
	Difference: 2864 (33%)

Pixel Rate

The GeForce 8600 GT 1GB GDDR3 will be much (more or less 50%) faster with regards to FSAA than the GeForce 820M, and also will be capable of handling higher screen resolutions while still performing well. (explain)

GeForce 8600 GT 1GB GDDR3		4320 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 1444 (50%)

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 max amount of data (counted in MB per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the memory bandwidth, 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 processed per second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.