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GeForce GT 640 DDR3 vs Radeon HD 4850 2GB
Intro
The GeForce GT 640 DDR3 has a GPU core clock speed of 900 MHz, and the 2048 MB of DDR3 memory runs at 1782 MHz through a 128-bit bus. It also features 384 SPUs, 32 TAUs, and 16 Raster Operation Units.Compare those specifications to the Radeon HD 4850 2GB, which has clock speeds of 625 MHz on the GPU, and 993 MHz on the 2048 MB of GDDR4 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
| GeForce GT 640 DDR3 |
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65 Watts |
| Radeon HD 4850 2GB |
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110 Watts |
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Memory Bandwidth
The Radeon HD 4850 2GB, in theory, should be a small bit faster than the GeForce GT 640 DDR3 overall. (explain)
| Radeon HD 4850 2GB |
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63552 MB/sec |
| GeForce GT 640 DDR3 |
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57024 MB/sec |
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Texel Rate
The GeForce GT 640 DDR3 will be a small bit (about 15%) better at texture filtering than the Radeon HD 4850 2GB. (explain)| GeForce GT 640 DDR3 |
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28800 Mtexels/sec |
| Radeon HD 4850 2GB |
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25000 Mtexels/sec |
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Pixel Rate
If running with a high screen resolution is important to you, then the GeForce GT 640 DDR3 is the winner, and very much so. (explain)| GeForce GT 640 DDR3 |
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14400 Mpixels/sec |
| Radeon HD 4850 2GB |
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10000 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 GT 640 DDR3Amazon.com
Check prices at:
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Radeon HD 4850 2GBAmazon.com
Check prices at:
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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 GT 640 DDR3 | Radeon HD 4850 2GB |
|---|---|---|
| Manufacturer | nVidia | AMD |
| Year | June 2012 | Jun 25, 2008 |
| Code Name | GK107 | RV770 PRO |
| Memory | 2048 MB | 2048 MB |
| Core Speed | 900 MHz | 625 MHz |
| Memory Speed | 3564 MHz | 1986 MHz |
| Power (Max TDP) | 65 watts | 110 watts |
| Bandwidth | 57024 MB/sec | 63552 MB/sec |
| Texel Rate | 28800 Mtexels/sec | 25000 Mtexels/sec |
| Pixel Rate | 14400 Mpixels/sec | 10000 Mpixels/sec |
| Unified Shaders | 384 | 800(160x5) |
| Texture Mapping Units | 32 | 40 |
| Render Output Units | 16 | 16 |
| Bus Type | DDR3 | GDDR4 |
| Bus Width | 128-bit | 256-bit |
| Fab Process | 28 nm | 55 nm |
| Transistors | 1300 million | 956 million |
| Bus | PCIe 3.0 x16 | PCIe 2.0 x16 |
| DirectX Version | DirectX 11.0 | DirectX 10.1 |
| OpenGL Version | OpenGL 4.2 | OpenGL 3.0 |
Memory Bandwidth: Bandwidth is the maximum amount of information (in units of MB per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total amount of 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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 get to the max fill rate.
GeForce GT 640 DDR3Amazon.com
Check prices at:
|
Radeon HD 4850 2GBAmazon.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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