GeForce GT 640 DDR3 vs GeForce GTX 460 SE

Intro

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

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

In theory, the GeForce GTX 460 SE will be 91% quicker than the GeForce GT 640 DDR3 overall, because of its greater data rate. (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 a small bit (about 8%) more effective at texture filtering 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 is a lot (about 44%) faster with regards to FSAA than the GeForce GT 640 DDR3, and also able to handle higher resolutions more effectively. (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: Memory bandwidth is the max amount of information (measured in MB per second) that can be moved over the external memory interface in a second. It's calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 texture map elements (texels) that are processed per second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.