 |
 |
|
|
|
GeForce GT 640 DDR3 vs GeForce GTX 660 Ti
Intro
The GeForce GT 640 DDR3 features a GPU core speed of 900 MHz, and the 2048 MB of DDR3 RAM runs at 1782 MHz through a 128-bit bus. It also is comprised of 384 Stream Processors, 32 Texture Address Units, and 16 ROPs.Compare all of that to the GeForce GTX 660 Ti, which makes use of a 28 nm design. nVidia has set the core speed at 915 MHz. The GDDR5 memory is set to run at a frequency of 1500 MHz on this card. It features 1344 SPUs as well as 112 Texture Address Units and 24 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
| GeForce GT 640 DDR3 |
|
65 Watts |
| GeForce GTX 660 Ti |
|
150 Watts |
|
|
Memory Bandwidth
In theory, the GeForce GTX 660 Ti should 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 |
|
|
Texel Rate
The GeForce GTX 660 Ti should be a lot (approximately 256%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)| GeForce GTX 660 Ti |
|
102480 Mtexels/sec |
| GeForce GT 640 DDR3 |
|
28800 Mtexels/sec |
|
|
Pixel Rate
The GeForce GTX 660 Ti should be quite a bit (about 53%) faster with regards to FSAA than the GeForce GT 640 DDR3, and also able to handle higher screen resolutions more effectively. (explain)| GeForce GTX 660 Ti |
|
21960 Mpixels/sec |
| GeForce GT 640 DDR3 |
|
14400 Mpixels/sec |
|
|
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
Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.
GeForce GT 640 DDR3Amazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
|
GeForce GTX 660 TiAmazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
|
Specifications
| Model | GeForce GT 640 DDR3 | GeForce GTX 660 Ti |
|---|---|---|
| Manufacturer | nVidia | nVidia |
| Year | June 2012 | August 2012 |
| Code Name | GK107 | GK104 |
| Fab Process | 28 nm | 28 nm |
| Bus | PCIe 3.0 x16 | PCIe 3.0 x16 |
| Memory | 2048 MB | 2048 MB |
| Core Speed | 900 MHz | 915 MHz |
| Shader Speed | 900 MHz | 915 MHz |
| Memory Speed | 1782 MHz (3564 MHz effective) | 1500 MHz (6000 MHz effective) |
| Unified Shaders | 384 | 1344 |
| Texture Mapping Units | 32 | 112 |
| Render Output Units | 16 | 24 |
| Bus Type | DDR3 | GDDR5 |
| Bus Width | 128-bit | 192-bit |
| DirectX Version | DirectX 11.1 | DirectX 11.1 |
| OpenGL Version | OpenGL 4.2 | OpenGL 4.3 |
| Power (Max TDP) | 65 watts | 150 watts |
| Shader Model | 5.0 | 5.0 |
| Bandwidth | 57024 MB/sec | 144000 MB/sec |
| Texel Rate | 28800 Mtexels/sec | 102480 Mtexels/sec |
| Pixel Rate | 14400 Mpixels/sec | 21960 Mpixels/sec |
Memory Bandwidth: Bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 can be applied per second. This 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 texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.
Comments
Be the first to leave a comment!