GeForce GT 450 (OEM) vs GeForce GT 640 DDR3

Intro

Compare all of that to the GeForce GT 640 DDR3, which features core 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 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GT 450 (OEM)		106 Watts
	Difference: 41 Watts (63%)

Memory Bandwidth

In theory, the GeForce GT 450 (OEM) should be a lot faster than the GeForce GT 640 DDR3 overall. (explain)

GeForce GT 450 (OEM)		96000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 38976 (68%)

Texel Rate

The GeForce GT 640 DDR3 should be a lot (more or less 52%) more effective at AF than the GeForce GT 450 (OEM). (explain)

GeForce GT 640 DDR3		28800 Mtexels/sec
GeForce GT 450 (OEM)		18960 Mtexels/sec
	Difference: 9840 (52%)

Pixel Rate

If using a high resolution is important to you, then the GeForce GT 450 (OEM) is a better choice, by a large margin. (explain)

GeForce GT 450 (OEM)		18960 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 4560 (32%)

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 transferred past the external memory interface in one second. The number is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total number of texture units by the core clock 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 applied in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.