GeForce GT 640 DDR3 vs GeForce GTX 460 1GB

Intro

Compare all of that to the GeForce GTX 460 1GB, which comes with GPU core speed of 675 MHz, and 1024 MB of GDDR5 memory running at 900 MHz through a 256-bit bus. It also is comprised of 336 Stream Processors, 56 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 460 1GB		160 Watts
	Difference: 95 Watts (146%)

Memory Bandwidth

The GeForce GTX 460 1GB should theoretically perform much faster than the GeForce GT 640 DDR3 overall. (explain)

GeForce GTX 460 1GB		115200 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 58176 (102%)

Texel Rate

The GeForce GTX 460 1GB should be a lot (approximately 31%) better at anisotropic filtering than the GeForce GT 640 DDR3. (explain)

GeForce GTX 460 1GB		37800 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 9000 (31%)

Pixel Rate

The GeForce GTX 460 1GB is much (more or less 50%) faster with regards to FSAA than the GeForce GT 640 DDR3, and should be capable of handling higher screen resolutions more effectively. (explain)

GeForce GTX 460 1GB		21600 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 7200 (50%)

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 (counted in megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.