GeForce 820M vs GeForce 8600 GT 1GB GDDR3

Intro

Compare all that to the GeForce 8600 GT 1GB GDDR3, which has a clock frequency of 540 MHz and a GDDR3 memory frequency of 700 MHz. It also features a 128-bit bus, and makes use of a 80 nm design. It is made up of 32 SPUs, 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

The GeForce 8600 GT 1GB GDDR3 should theoretically be quite a bit 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 a lot (about 33%) faster with regards to anisotropic filtering 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

If using a high screen resolution is important to you, then the GeForce 8600 GT 1GB GDDR3 is superior to the GeForce 820M, by a large margin. (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 information (in units of megabytes per second) that can be transported over the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This number is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video 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 - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.