GeForce GT 640 DDR3 vs GeForce GTX 460 SE

Intro

Compare all that to the GeForce GTX 460 SE, which makes use of a 40 nm design. nVidia has clocked the core speed at 650 MHz. The GDDR5 RAM runs at a frequency of 850 MHz on this particular model. It features 288 SPUs as well as 48 Texture Address Units and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 460 SE		150 Watts
	Difference: 85 Watts (131%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 460 SE should in theory be quite a bit better than the GeForce GT 640 DDR3 in general. (explain)

GeForce GTX 460 SE		108800 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 51776 (91%)

Texel Rate

The GeForce GTX 460 SE is just a bit (more or less 8%) better at AF than the GeForce GT 640 DDR3. (explain)

GeForce GTX 460 SE		31200 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 2400 (8%)

Pixel Rate

The GeForce GTX 460 SE will be quite a bit (approximately 44%) better at AA than the GeForce GT 640 DDR3, and should be capable of handling higher resolutions without losing too much performance. (explain)

GeForce GTX 460 SE		20800 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 6400 (44%)

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 transferred across the external memory interface in a second. It's worked out by multiplying the bus width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. 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 amount of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the core 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 also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.