GeForce GT 640 DDR3 vs GeForce GTX 970

Intro

Compare those specs to the GeForce GTX 970, which features a GPU core clock speed of 1050 MHz, and 4096 MB of GDDR5 RAM set to run at 1750 MHz through a 256-bit bus. It also is made up of 1664 SPUs, 104 TAUs, and 64 ROPs.

Display Graphs

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Benchmarks

These are real-world performance benchmarks that were submitted by Hardware Compare users. The scores seen here are the average of all benchmarks submitted for each respective test and hardware.

3DMark Fire Strike Graphics Score

GeForce GTX 970		10867 points
GeForce GT 640 DDR3		1560 points
	Difference: 9307 (597%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 970		145 Watts
	Difference: 80 Watts (123%)

Memory Bandwidth

In theory, the GeForce GTX 970 is 293% quicker than the GeForce GT 640 DDR3 overall, due to its higher data rate. (explain)

GeForce GTX 970		224000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 166976 (293%)

Texel Rate

The GeForce GTX 970 is quite a bit (approximately 279%) more effective at anisotropic filtering than the GeForce GT 640 DDR3. (explain)

GeForce GTX 970		109200 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 80400 (279%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the GeForce GTX 970 is the winner, by far. (explain)

GeForce GTX 970		67200 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 52800 (367%)

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 max amount of data (counted in MB per second) that can be transferred past the external memory interface within a second. The number is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. 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 amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.