GeForce 820M vs GeForce 8500 GT

Intro

Compare all of that to the GeForce 8500 GT, which has GPU core speed of 450 MHz, and 512 MB of DDR2 memory set to run at 400 MHz through a 128-bit bus. It also features 16 SPUs, 8 Texture Address Units, and 4 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 820M		15 Watts
GeForce 8500 GT		45 Watts
	Difference: 30 Watts (200%)

Memory Bandwidth

The GeForce 820M, in theory, should perform quite a bit faster than the GeForce 8500 GT overall. (explain)

GeForce 820M		16000 MB/sec
GeForce 8500 GT		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The GeForce 820M will be a lot (approximately 220%) faster with regards to texture filtering than the GeForce 8500 GT. (explain)

GeForce 820M		11504 Mtexels/sec
GeForce 8500 GT		3600 Mtexels/sec
	Difference: 7904 (220%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce 820M is a better choice, by far. (explain)

GeForce 820M		2876 Mpixels/sec
GeForce 8500 GT		1800 Mpixels/sec
	Difference: 1076 (60%)

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 largest amount of data (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 interface width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is worked out by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the video 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 write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of 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 of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.