GeForce GT 640 DDR3 vs GeForce GTX 660 Ti

Intro

Compare all of that to the GeForce GTX 660 Ti, which comes with a clock speed of 915 MHz and a GDDR5 memory frequency of 1500 MHz. It also makes use of a 192-bit memory bus, and uses a 28 nm design. It features 1344 SPUs, 112 TAUs, and 24 ROPs.

Display Graphs

Hide Graphs

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 660 Ti		6013 points
GeForce GT 640 DDR3		1560 points
	Difference: 4453 (285%)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 640 DDR3		65 Watts
GeForce GTX 660 Ti		150 Watts
	Difference: 85 Watts (131%)

Memory Bandwidth

The GeForce GTX 660 Ti should theoretically perform quite a bit faster than the GeForce GT 640 DDR3 in general. (explain)

GeForce GTX 660 Ti		144000 MB/sec
GeForce GT 640 DDR3		57024 MB/sec
	Difference: 86976 (153%)

Texel Rate

The GeForce GTX 660 Ti should be quite a bit (about 256%) faster with regards to AF than the GeForce GT 640 DDR3. (explain)

GeForce GTX 660 Ti		102480 Mtexels/sec
GeForce GT 640 DDR3		28800 Mtexels/sec
	Difference: 73680 (256%)

Pixel Rate

If running with high levels of AA is important to you, then the GeForce GTX 660 Ti is superior to the GeForce GT 640 DDR3, and very much so. (explain)

GeForce GTX 660 Ti		21960 Mpixels/sec
GeForce GT 640 DDR3		14400 Mpixels/sec
	Difference: 7560 (53%)

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 largest amount of data (measured in MB per second) that can be transported past the external memory interface within a second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better 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 number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total texture units of the card 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 in a second.

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