GeForce GT 640 DDR3 vs GeForce GTX 970

Intro

Compare those specifications to the GeForce GTX 970, which makes use of a 28 nm design. nVidia has set the core speed at 1050 MHz. The GDDR5 memory works at a speed of 1750 MHz on this particular card. It features 1664 SPUs as well as 104 TAUs and 64 Rasterization Operator Units.

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

Theoretically, the GeForce GTX 970 should perform much faster than the GeForce GT 640 DDR3 in general. (explain)

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

Texel Rate

The GeForce GTX 970 will be much (more or less 279%) better at texture 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

The GeForce GTX 970 is quite a bit (approximately 367%) more effective at FSAA than the GeForce GT 640 DDR3, and should be capable of handling higher screen resolutions without losing too much performance. (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 maximum amount of data (counted in MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.