GeForce 820M vs GeForce 8600 GT 1GB DDR2

Intro

Compare that to the GeForce 8600 GT 1GB DDR2, which has a clock frequency of 540 MHz and a DDR2 memory frequency of 400 MHz. It also features a 128-bit bus, and makes use of a 80 nm design. It features 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 DDR2		47 Watts
	Difference: 32 Watts (213%)

Memory Bandwidth

In theory, the GeForce 820M should perform much faster than the GeForce 8600 GT 1GB DDR2 in general. (explain)

GeForce 820M		16000 MB/sec
GeForce 8600 GT 1GB DDR2		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The GeForce 820M will be a lot (approximately 33%) better at texture filtering than the GeForce 8600 GT 1GB DDR2. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8600 GT 1GB DDR2		8640 Mtexels/sec
	Difference: 2864 (33%)

Pixel Rate

The GeForce 8600 GT 1GB DDR2 should be quite a bit (approximately 50%) better at full screen anti-aliasing than the GeForce 820M, and capable of handling higher resolutions without losing too much performance. (explain)

GeForce 8600 GT 1GB 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 data (in units of megabytes per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. 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 can be processed per second. This is calculated by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.