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GeForce 9800 GT 512MB vs GeForce GT 640 DDR3
Intro
The GeForce 9800 GT 512MB uses a 65/55 nm design. nVidia has clocked the core speed at 600 MHz. The GDDR3 memory is set to run at a frequency of 900 MHz on this particular model. It features 112 SPUs as well as 56 Texture Address Units and 16 Rasterization Operator Units.Compare those specs to the GeForce GT 640 DDR3, which makes use of a 28 nm design. nVidia has set the core speed at 900 MHz. The DDR3 memory is set to run at a speed of 1782 MHz on this particular card. It features 384 SPUs as well as 32 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
| GeForce GT 640 DDR3 |
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65 Watts |
| GeForce 9800 GT 512MB |
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105 Watts |
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Memory Bandwidth
The GeForce 9800 GT 512MB, in theory, should be a bit faster than the GeForce GT 640 DDR3 overall. (explain)
| GeForce 9800 GT 512MB |
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57600 MB/sec |
| GeForce GT 640 DDR3 |
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57024 MB/sec |
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Texel Rate
The GeForce 9800 GT 512MB should be a bit (more or less 17%) faster with regards to texture filtering than the GeForce GT 640 DDR3. (explain)| GeForce 9800 GT 512MB |
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33600 Mtexels/sec |
| GeForce GT 640 DDR3 |
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28800 Mtexels/sec |
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Pixel Rate
If using lots of anti-aliasing is important to you, then the GeForce GT 640 DDR3 is superior to the GeForce 9800 GT 512MB, by far. (explain)| GeForce GT 640 DDR3 |
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14400 Mpixels/sec |
| GeForce 9800 GT 512MB |
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9600 Mpixels/sec |
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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
GeForce 9800 GT 512MBAmazon.com
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GeForce GT 640 DDR3Amazon.com
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Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Specifications
| Model | GeForce 9800 GT 512MB | GeForce GT 640 DDR3 |
|---|---|---|
| Manufacturer | nVidia | nVidia |
| Year | July 2008 | June 2012 |
| Code Name | G92a/b | GK107 |
| Memory | 512 MB | 2048 MB |
| Core Speed | 600 MHz | 900 MHz |
| Memory Speed | 1800 MHz | 3564 MHz |
| Power (Max TDP) | 105 watts | 65 watts |
| Bandwidth | 57600 MB/sec | 57024 MB/sec |
| Texel Rate | 33600 Mtexels/sec | 28800 Mtexels/sec |
| Pixel Rate | 9600 Mpixels/sec | 14400 Mpixels/sec |
| Unified Shaders | 112 | 384 |
| Texture Mapping Units | 56 | 32 |
| Render Output Units | 16 | 16 |
| Bus Type | GDDR3 | DDR3 |
| Bus Width | 256-bit | 128-bit |
| Fab Process | 65/55 nm | 28 nm |
| Transistors | 754 million | 1300 million |
| Bus | PCIe x16 2.0 | PCIe 3.0 x16 |
| DirectX Version | DirectX 10 | DirectX 11.0 |
| OpenGL Version | OpenGL 3.0 | OpenGL 4.2 |
Memory Bandwidth: Bandwidth is the maximum amount of data (counted in megabytes per second) that can be transferred over the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.
GeForce 9800 GT 512MBAmazon.com
Check prices at:
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GeForce GT 640 DDR3Amazon.com
Check prices at:
|
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
|
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