GeForce GT 640 DDR3 vs GeForce GTX 260 Core 216

Intro

Compare those specifications to the GeForce GTX 260 Core 216, which comes with core clock speeds of 576 MHz on the GPU, and 999 MHz on the 896 MB of GDDR3 memory. It features 216 SPUs as well as 72 TAUs and 28 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 260 Core 216		202 Watts
	Difference: 137 Watts (211%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 260 Core 216 should in theory be much superior to the GeForce GT 640 DDR3 overall. (explain)

GeForce GTX 260 Core 216		111888 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 54864 (96%)

Texel Rate

The GeForce GTX 260 Core 216 will be much (more or less 44%) more effective at texture filtering than the GeForce GT 640 DDR3. (explain)

GeForce GTX 260 Core 216		41472 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 12672 (44%)

Pixel Rate

If using high levels of AA is important to you, then the GeForce GTX 260 Core 216 is the winner, but only just. (explain)

GeForce GTX 260 Core 216		16128 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 1728 (12%)

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 maximum amount of information (counted in megabytes per second) that can be transferred past the external memory interface in one second. It is calculated by multiplying the card's bus width by its memory speed. If the card has DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels the video card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core 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 output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.