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Radeon HD 4790 vs Radeon HD 7990
Intro
The Radeon HD 4790 makes use of a 55 nm design. AMD has clocked the core frequency at 600 MHz. The GDDR5 memory is set to run at a frequency of 800 MHz on this model. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.Compare all that to the Radeon HD 7990, which comes with clock speeds of 950 MHz on the GPU, and 1500 MHz on the 3072 MB of GDDR5 RAM. It features 2048 SPUs along with 128 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Memory Bandwidth
The Radeon HD 7990 should theoretically perform quite a bit faster than the Radeon HD 4790 overall. (explain)
| Radeon HD 7990 |
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576000 MB/sec |
| Radeon HD 4790 |
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102400 MB/sec |
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Texel Rate
The Radeon HD 7990 is much (approximately 1167%) better at texture filtering than the Radeon HD 4790. (explain)| Radeon HD 7990 |
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243200 Mtexels/sec |
| Radeon HD 4790 |
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19200 Mtexels/sec |
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Pixel Rate
The Radeon HD 7990 will be quite a bit (approximately 533%) better at AA than the Radeon HD 4790, and able to handle higher resolutions while still performing well. (explain)| Radeon HD 7990 |
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60800 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 4790Amazon.com
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Radeon HD 7990Amazon.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 4790 | Radeon HD 7990 |
|---|---|---|
| Manufacturer | AMD | AMD |
| Year | 2009 | April 2013 |
| Code Name | RV790 | Malta |
| Memory | 512 MB | 3072 MB (x2) |
| Core Speed | 600 MHz | 950 MHz (x2) |
| Memory Speed | 3200 MHz | 6000 MHz (x2) |
| Power (Max TDP) | (Unknown) watts | 375 watts |
| Bandwidth | 102400 MB/sec | 576000 MB/sec |
| Texel Rate | 19200 Mtexels/sec | 243200 Mtexels/sec |
| Pixel Rate | 9600 Mpixels/sec | 60800 Mpixels/sec |
| Unified Shaders | 640(128x5) | 2048 (x2) |
| Texture Mapping Units | 32 | 128 (x2) |
| Render Output Units | 16 | 32 (x2) |
| Bus Type | GDDR5 | GDDR5 |
| Bus Width | 256-bit | 384-bit (x2) |
| Fab Process | 55 nm | 28 nm |
| Transistors | 959 million | 4313 million |
| Bus | PCIe 2.0 x16 | PCIe 3.0 x16 |
| DirectX Version | DirectX 10.1 | DirectX 11.1 |
| OpenGL Version | OpenGL 3.0 | OpenGL 4.3 |
Memory Bandwidth: Bandwidth is the max amount of data (counted in MB per second) that can be moved past the external memory interface within a second. It is calculated by multiplying the card's interface width by its memory speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the graphics 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 number of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units 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 output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.
Radeon HD 4790Amazon.com
Check prices at:
|
Radeon HD 7990Amazon.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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