GeForce 820M vs GeForce 8600 GT 512MB DDR2

Intro

Compare those specs to the GeForce 8600 GT 512MB DDR2, which has clock speeds of 540 MHz on the GPU, and 400 MHz on the 512 MB of DDR2 RAM. It features 32 SPUs as well as 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 512MB DDR2		47 Watts
	Difference: 32 Watts (213%)

Memory Bandwidth

Performance-wise, the GeForce 820M should theoretically be much superior to the GeForce 8600 GT 512MB DDR2 overall. (explain)

GeForce 820M		16000 MB/sec
GeForce 8600 GT 512MB DDR2		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The GeForce 820M should be a lot (more or less 33%) better at anisotropic filtering than the GeForce 8600 GT 512MB DDR2. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8600 GT 512MB DDR2		8640 Mtexels/sec
	Difference: 2864 (33%)

Pixel Rate

The GeForce 8600 GT 512MB DDR2 will be a lot (approximately 50%) more effective at anti-aliasing than the GeForce 820M, and will be able to handle higher resolutions more effectively. (explain)

GeForce 8600 GT 512MB DDR2		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: Bandwidth is the max amount of information (measured in megabytes per second) that can be moved across the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 maximum amount of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.