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Radeon HD 7870 vs Radeon R5 M255
Intro
The Radeon HD 7870 has a core clock frequency of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 256-bit bus, and makes use of a 28 nm design. It is comprised of 1280 SPUs, 80 TAUs, and 32 ROPs.Compare those specs to the Radeon R5 M255, which has GPU clock speed of 940 MHz, and 2048 MB of DDR3 RAM set to run at 1000 MHz through a 64-bit bus. It also is made up of 320 Stream Processors, 20 TAUs, and 8 ROPs.
Power Usage and Theoretical Benchmarks
Memory Bandwidth
The Radeon HD 7870, in theory, should be much faster than the Radeon R5 M255 in general. (explain)
| Radeon HD 7870 |
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153600 MB/sec |
| Radeon R5 M255 |
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16000 MB/sec |
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Texel Rate
The Radeon HD 7870 is much (about 326%) faster with regards to anisotropic filtering than the Radeon R5 M255. (explain)| Radeon HD 7870 |
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80000 Mtexels/sec |
| Radeon R5 M255 |
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18800 Mtexels/sec |
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Pixel Rate
If using a high screen resolution is important to you, then the Radeon HD 7870 is superior to the Radeon R5 M255, by a large margin. (explain)| Radeon HD 7870 |
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32000 Mpixels/sec |
| Radeon R5 M255 |
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7520 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
Radeon HD 7870Amazon.com
Check prices at:
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Radeon R5 M255Amazon.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 | Radeon HD 7870 | Radeon R5 M255 |
|---|---|---|
| Manufacturer | AMD | AMD |
| Year | March 2012 | June 2014 |
| Code Name | Pitcairn XT | Jet Pro |
| Memory | 2048 MB | 2048 MB |
| Core Speed | 1000 MHz | 940 MHz |
| Memory Speed | 4800 MHz | 2000 MHz |
| Power (Max TDP) | 175 watts | (Unknown) watts |
| Bandwidth | 153600 MB/sec | 16000 MB/sec |
| Texel Rate | 80000 Mtexels/sec | 18800 Mtexels/sec |
| Pixel Rate | 32000 Mpixels/sec | 7520 Mpixels/sec |
| Unified Shaders | 1280 | 320 |
| Texture Mapping Units | 80 | 20 |
| Render Output Units | 32 | 8 |
| Bus Type | GDDR5 | DDR3 |
| Bus Width | 256-bit | 64-bit |
| Fab Process | 28 nm | 28 nm |
| Transistors | 2800 million | (Unknown) million |
| Bus | PCIe 3.0 x16 | PCIe 3.0 x8 |
| DirectX Version | DirectX 11.1 | DirectX 11.2 |
| OpenGL Version | OpenGL 4.2 | OpenGL 4.3 |
Memory Bandwidth: Memory bandwidth is the maximum amount of information (in units of MB per second) that can be moved across 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, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.
Radeon HD 7870Amazon.com
Check prices at:
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Radeon R5 M255Amazon.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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