GeForce GT 320 vs GeForce GT 640 DDR3

Intro

Compare those specs to the GeForce GT 640 DDR3, which features core speeds of 900 MHz on the GPU, and 1782 MHz on the 2048 MB of DDR3 RAM. It features 384 SPUs as well as 32 Texture Address Units and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 320		43 Watts
GeForce GT 640 DDR3		65 Watts
	Difference: 22 Watts (51%)

Memory Bandwidth

Theoretically, the GeForce GT 640 DDR3 should perform a lot faster than the GeForce GT 320 in general. (explain)

GeForce GT 640 DDR3		57024 MB/sec
GeForce GT 320		25280 MB/sec
	Difference: 31744 (126%)

Texel Rate

The GeForce GT 640 DDR3 should be quite a bit (more or less 122%) faster with regards to anisotropic filtering than the GeForce GT 320. (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce GT 320		12960 Mtexels/sec
	Difference: 15840 (122%)

Pixel Rate

The GeForce GT 640 DDR3 should be a lot (more or less 233%) faster with regards to anti-aliasing than the GeForce GT 320, and will be capable of handling higher screen resolutions more effectively. (explain)

GeForce GT 640 DDR3		14400 Mpixels/sec
GeForce GT 320		4320 Mpixels/sec
	Difference: 10080 (233%)

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 maximum amount of data (in units of MB per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total texture units by the core clock speed of the chip. The better the texel rate, 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 maximum amount of pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.