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Radeon HD 3870 X2 512MB vs Radeon HD 4790
Intro
The Radeon HD 3870 X2 512MB makes use of a 55 nm design. AMD has set the core frequency at 825 MHz. The GDDR3 memory is set to run at a speed of 900 MHz on this model. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 Rasterization Operator Units.Compare those specs to the Radeon HD 4790, which makes use of a 55 nm design. AMD has clocked the core frequency at 600 MHz. The GDDR5 RAM works at a frequency of 800 MHz on this card. It features 640(128x5) SPUs as well as 32 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Memory Bandwidth
Theoretically speaking, the Radeon HD 3870 X2 512MB will be 13% faster than the Radeon HD 4790 in general, because of its higher data rate. (explain)
| Radeon HD 3870 X2 512MB |
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115200 MB/sec |
| Radeon HD 4790 |
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102400 MB/sec |
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Texel Rate
The Radeon HD 3870 X2 512MB is quite a bit (about 38%) better at anisotropic filtering than the Radeon HD 4790. (explain)| Radeon HD 3870 X2 512MB |
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26400 Mtexels/sec |
| Radeon HD 4790 |
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19200 Mtexels/sec |
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Pixel Rate
The Radeon HD 3870 X2 512MB is quite a bit (about 175%) more effective at full screen anti-aliasing than the Radeon HD 4790, and able to handle higher resolutions without slowing down too much. (explain)| Radeon HD 3870 X2 512MB |
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26400 Mpixels/sec |
| Radeon HD 4790 |
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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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
Price Comparison
Radeon HD 3870 X2 512MBAmazon.com
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Radeon HD 4790Amazon.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 | Radeon HD 3870 X2 512MB | Radeon HD 4790 |
|---|---|---|
| Manufacturer | AMD | AMD |
| Year | Jan 28, 2008 | 2009 |
| Code Name | R680 | RV790 |
| Memory | 512 MB (x2) | 512 MB |
| Core Speed | 825 MHz (x2) | 600 MHz |
| Memory Speed | 1800 MHz (x2) | 3200 MHz |
| Power (Max TDP) | (Unknown) watts | (Unknown) watts |
| Bandwidth | 115200 MB/sec | 102400 MB/sec |
| Texel Rate | 26400 Mtexels/sec | 19200 Mtexels/sec |
| Pixel Rate | 26400 Mpixels/sec | 9600 Mpixels/sec |
| Unified Shaders | 320(64x5) (x2) | 640(128x5) |
| Texture Mapping Units | 16 (x2) | 32 |
| Render Output Units | 16 (x2) | 16 |
| Bus Type | GDDR3 | GDDR5 |
| Bus Width | 256-bit (x2) | 256-bit |
| Fab Process | 55 nm | 55 nm |
| Transistors | (Unknown) million | 959 million |
| Bus | PCIe 2.0 x16/(internal PCIe 1.1 x16) | PCIe 2.0 x16 |
| DirectX Version | DirectX 10.1 | DirectX 10.1 |
| OpenGL Version | OpenGL 3.0 | OpenGL 3.0 |
Memory Bandwidth: Bandwidth is the maximum amount of information (measured in MB per second) that can be transferred past the external memory interface in a second. The number is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher 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 in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. 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 fill rate also depends on many 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.
Radeon HD 3870 X2 512MBAmazon.com
Check prices at:
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Radeon HD 4790Amazon.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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