GeForce 820M vs GeForce GTX 260

Intro

Compare those specifications to the GeForce GTX 260, which comes with a GPU core clock speed of 576 MHz, and 896 MB of GDDR3 memory set to run at 999 MHz through a 448-bit bus. It also is made up of 192 SPUs, 64 TAUs, and 28 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce GTX 260		182 Watts
	Difference: 167 Watts (1113%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 260 should be a lot faster than the GeForce 820M in general. (explain)

GeForce GTX 260		111888 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 95888 (599%)

Texel Rate

The GeForce GTX 260 is a lot (about 220%) faster with regards to texture filtering than the GeForce 820M. (explain)

GeForce GTX 260		36864 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 25360 (220%)

Pixel Rate

The GeForce GTX 260 should be quite a bit (more or less 461%) faster with regards to FSAA than the GeForce 820M, and also capable of handling higher resolutions more effectively. (explain)

GeForce GTX 260		16128 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 13252 (461%)

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 past the external memory interface in one second. It is worked out by multiplying the interface width by the speed of its memory. If the card has DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. 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 number of texture map elements (texels) that are processed in one second. This is calculated by multiplying the total amount of texture units by the core clock 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 applied per second.

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