GeForce 830M vs GeForce GT 640 DDR3

Intro

Compare that to the GeForce GT 640 DDR3, which comes with core clock speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 RAM. It features 384 SPUs along with 32 TAUs and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 830M		25 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 40 Watts (160%)

Memory Bandwidth

As far as performance goes, the GeForce GT 640 DDR3 should in theory be a lot superior to the GeForce 830M in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce 830M		14400 MB/sec
	Difference: 42624 (296%)

Texel Rate

The GeForce GT 640 DDR3 is much (more or less 75%) faster with regards to texture filtering than the GeForce 830M. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce 830M		16464 Mtexels/sec
	Difference: 12336 (75%)

Pixel Rate

The GeForce GT 640 DDR3 is much (more or less 75%) more effective at AA than the GeForce 830M, and should be able to handle higher resolutions while still performing well. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce 830M		8232 Mpixels/sec
	Difference: 6168 (75%)

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 data (measured in megabytes per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better 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 texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the card will be at handling 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 chip could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.