GeForce 830M vs GeForce GT 640 DDR3

Intro

Compare all of that to the GeForce GT 640 DDR3, which comes with clock speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 memory. It features 384 SPUs along with 32 Texture Address Units 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

Theoretically speaking, the GeForce GT 640 DDR3 should perform quite a bit faster than 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 should be quite a bit (about 75%) better at anisotropic filtering than the GeForce 830M. (explain)

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

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is a better choice, by a large margin. (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 maximum amount of information (in units of MB per second) that can be transferred over 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 type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the graphics card will be at handling 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 the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.