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Radeon HD 3870 X2 512MB vs Radeon HD 6990
Intro
The Radeon HD 3870 X2 512MB uses a 55 nm design. AMD has clocked the core speed at 825 MHz. The GDDR3 memory is set to run at a frequency of 900 MHz on this specific card. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator Units.Compare those specifications to the Radeon HD 6990, which features a clock frequency of 830 MHz and a GDDR5 memory speed of 1250 MHz. It also features a 256-bit bus, and makes use of a 40 nm design. It is comprised of 1536 SPUs, 96 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Memory Bandwidth
In theory, the Radeon HD 6990 should be 178% quicker than the Radeon HD 3870 X2 512MB in general, due to its greater data rate. (explain)
| Radeon HD 6990 |
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320000 MB/sec |
| Radeon HD 3870 X2 512MB |
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115200 MB/sec |
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Texel Rate
The Radeon HD 6990 should be much (approximately 504%) more effective at texture filtering than the Radeon HD 3870 X2 512MB. (explain)| Radeon HD 6990 |
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159360 Mtexels/sec |
| Radeon HD 3870 X2 512MB |
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26400 Mtexels/sec |
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Pixel Rate
The Radeon HD 6990 is much (approximately 101%) better at AA than the Radeon HD 3870 X2 512MB, and able to handle higher screen resolutions better. (explain)| Radeon HD 6990 |
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53120 Mpixels/sec |
| Radeon HD 3870 X2 512MB |
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26400 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 6990Amazon.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 6990 |
|---|---|---|
| Manufacturer | AMD | AMD |
| Year | Jan 28, 2008 | March 2011 |
| Code Name | R680 | Antilles |
| Memory | 512 MB (x2) | 2048 MB (x2) |
| Core Speed | 825 MHz (x2) | 830 MHz (x2) |
| Memory Speed | 1800 MHz (x2) | 5000 MHz (x2) |
| Power (Max TDP) | (Unknown) watts | 375 watts |
| Bandwidth | 115200 MB/sec | 320000 MB/sec |
| Texel Rate | 26400 Mtexels/sec | 159360 Mtexels/sec |
| Pixel Rate | 26400 Mpixels/sec | 53120 Mpixels/sec |
| Unified Shaders | 320(64x5) (x2) | 1536 (x2) |
| Texture Mapping Units | 16 (x2) | 96 (x2) |
| Render Output Units | 16 (x2) | 32 (x2) |
| Bus Type | GDDR3 | GDDR5 |
| Bus Width | 256-bit (x2) | 256-bit (x2) |
| Fab Process | 55 nm | 40 nm |
| Transistors | (Unknown) million | 2640 million |
| Bus | PCIe 2.0 x16/(internal PCIe 1.1 x16) | PCIe 2.1 x16 |
| DirectX Version | DirectX 10.1 | DirectX 11 |
| OpenGL Version | OpenGL 3.0 | OpenGL 4.1 |
Memory Bandwidth: Memory bandwidth is the maximum amount of data (measured in megabytes per second) that can be moved across the external memory interface in a second. The number is worked out by multiplying the card's bus width by its memory speed. If the card has DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. 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 can be applied in one second. This figure is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of ROPs by the the core 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 lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.
Radeon HD 3870 X2 512MBAmazon.com
Check prices at:
|
Radeon HD 6990Amazon.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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