GeForce 840M vs GeForce 8600 GT 1GB DDR2

Intro

Compare that to the GeForce 8600 GT 1GB DDR2, which comes with core speeds of 540 MHz on the GPU, and 400 MHz on the 1024 MB of DDR2 memory. It features 32 SPUs along with 16 Texture Address Units and 8 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 840M		30 Watts
GeForce 8600 GT 1GB DDR2		47 Watts
	Difference: 17 Watts (57%)

Memory Bandwidth

Theoretically speaking, the GeForce 840M is 25% faster than the GeForce 8600 GT 1GB DDR2 in general, because of its higher bandwidth. (explain)

GeForce 840M		16000 MB/sec
GeForce 8600 GT 1GB DDR2		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The GeForce 840M will be much (about 186%) more effective at anisotropic filtering than the GeForce 8600 GT 1GB DDR2. (explain)

GeForce 840M		24696 Mtexels/sec
GeForce 8600 GT 1GB DDR2		8640 Mtexels/sec
	Difference: 16056 (186%)

Pixel Rate

The GeForce 840M should be quite a bit (more or less 91%) more effective at full screen anti-aliasing than the GeForce 8600 GT 1GB DDR2, and also able to handle higher resolutions better. (explain)

GeForce 840M		8232 Mpixels/sec
GeForce 8600 GT 1GB DDR2		4320 Mpixels/sec
	Difference: 3912 (91%)

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 information (in units of MB per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster 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 number is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.