GeForce GT 340 1GB vs GeForce GT 640 DDR3

Intro

Compare those specifications to the GeForce GT 640 DDR3, which has core 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 GT 640 DDR3		65 Watts
GeForce GT 340 1GB		69 Watts
	Difference: 4 Watts (6%)

Memory Bandwidth

The GeForce GT 640 DDR3 should theoretically perform a small bit faster than the GeForce GT 340 1GB in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce GT 340 1GB		54400 MB/sec
	Difference: 2624 (5%)

Texel Rate

The GeForce GT 640 DDR3 will be a lot (approximately 64%) faster with regards to anisotropic filtering than the GeForce GT 340 1GB. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce GT 340 1GB		17600 Mtexels/sec
	Difference: 11200 (64%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce GT 340 1GB, by far. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce GT 340 1GB		4400 Mpixels/sec
	Difference: 10000 (227%)

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: Bandwidth is the largest amount of data (in units of megabytes per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, 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 AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This is calculated by multiplying the total texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The figure is worked out 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 many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.