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GeForce GT 640 DDR3 vs Radeon HD 4850 1GB
Intro
The GeForce GT 640 DDR3 features a core clock frequency of 900 MHz and a DDR3 memory frequency of 1782 MHz. It also uses a 128-bit memory bus, and uses a 28 nm design. It features 384 SPUs, 32 TAUs, and 16 Raster Operation Units.Compare that to the Radeon HD 4850 1GB, which has GPU core speed of 625 MHz, and 1024 MB of GDDR4 RAM running at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) SPUs, 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 1GB |
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110 Watts |
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Memory Bandwidth
In theory, the Radeon HD 4850 1GB should be just a bit faster than the GeForce GT 640 DDR3 in general. (explain)
| Radeon HD 4850 1GB |
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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 is a little bit (more or less 15%) faster with regards to AF than the Radeon HD 4850 1GB. (explain)| GeForce GT 640 DDR3 |
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28800 Mtexels/sec |
| Radeon HD 4850 1GB |
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25000 Mtexels/sec |
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Pixel Rate
The GeForce GT 640 DDR3 will be much (more or less 44%) more effective at anti-aliasing than the Radeon HD 4850 1GB, and also will be capable of handling higher resolutions without losing too much performance. (explain)| GeForce GT 640 DDR3 |
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14400 Mpixels/sec |
| Radeon HD 4850 1GB |
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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 1GBAmazon.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 1GB |
|---|---|---|
| Manufacturer | nVidia | AMD |
| Year | June 2012 | Jun 25, 2008 |
| Code Name | GK107 | RV770 PRO |
| Memory | 2048 MB | 1024 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: Memory bandwidth is the maximum amount of data (in units of megabytes per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total number of texture units of the card 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 in a second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs 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 rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.
GeForce GT 640 DDR3Amazon.com
Check prices at:
|
Radeon HD 4850 1GBAmazon.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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