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Radeon HD 3850 X2 vs Radeon HD 4870 2GB
Intro
The Radeon HD 3850 X2 makes use of a 55 nm design. AMD has set the core speed at 668 MHz. The GDDR3 memory is set to run at a speed of 828 MHz on this particular card. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 Rasterization Operator Units.Compare those specs to the Radeon HD 4870 2GB, which comes with clock speeds of 750 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR5 RAM. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Memory Bandwidth
The Radeon HD 4870 2GB should theoretically perform just a bit faster than the Radeon HD 3850 X2 in general. (explain)
| Radeon HD 4870 2GB |
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115200 MB/sec |
| Radeon HD 3850 X2 |
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105984 MB/sec |
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Texel Rate
The Radeon HD 4870 2GB should be a lot (more or less 40%) better at texture filtering than the Radeon HD 3850 X2. (explain)| Radeon HD 4870 2GB |
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30000 Mtexels/sec |
| Radeon HD 3850 X2 |
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21376 Mtexels/sec |
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Pixel Rate
If running with lots of anti-aliasing is important to you, then the Radeon HD 3850 X2 is superior to the Radeon HD 4870 2GB, by a large margin. (explain)| Radeon HD 3850 X2 |
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21376 Mpixels/sec |
| Radeon HD 4870 2GB |
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12000 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 3850 X2Amazon.com
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Radeon HD 4870 2GBAmazon.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 3850 X2 | Radeon HD 4870 2GB |
|---|---|---|
| Manufacturer | AMD | AMD |
| Year | Apr 4, 2008 | Jun 25, 2008 |
| Code Name | RV670 PRO | RV770 XT |
| Memory | 512 MB (x2) | 2048 MB |
| Core Speed | 668 MHz (x2) | 750 MHz |
| Memory Speed | 1656 MHz (x2) | 3600 MHz |
| Power (Max TDP) | (Unknown) watts | 150 watts |
| Bandwidth | 105984 MB/sec | 115200 MB/sec |
| Texel Rate | 21376 Mtexels/sec | 30000 Mtexels/sec |
| Pixel Rate | 21376 Mpixels/sec | 12000 Mpixels/sec |
| Unified Shaders | 320(64x5) (x2) | 800(160x5) |
| Texture Mapping Units | 16 (x2) | 40 |
| 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 | 956 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 max amount of information (measured in MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.
Radeon HD 3850 X2Amazon.com
Check prices at:
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Radeon HD 4870 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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