GeForce 820M vs GeForce GTX 285 2GB

Intro

Compare those specs to the GeForce GTX 285 2GB, which comes with GPU clock speed of 648 MHz, and 2048 MB of GDDR3 RAM running at 1242 MHz through a 512-bit bus. It also is comprised of 240 Stream Processors, 80 TAUs, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce GTX 285 2GB		204 Watts
	Difference: 189 Watts (1260%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 285 2GB should perform much faster than the GeForce 820M in general. (explain)

GeForce GTX 285 2GB		158976 MB/sec
GeForce 820M		16000 MB/sec
	Difference: 142976 (894%)

Texel Rate

The GeForce GTX 285 2GB is quite a bit (more or less 351%) better at AF than the GeForce 820M. (explain)

GeForce GTX 285 2GB		51840 Mtexels/sec
GeForce 820M		11504 Mtexels/sec
	Difference: 40336 (351%)

Pixel Rate

The GeForce GTX 285 2GB will be much (approximately 621%) better at anti-aliasing than the GeForce 820M, and also should be able to handle higher screen resolutions while still performing well. (explain)

GeForce GTX 285 2GB		20736 Mpixels/sec
GeForce 820M		2876 Mpixels/sec
	Difference: 17860 (621%)

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 in one second. It's calculated by multiplying the interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 once 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 AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.