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Radeon HD 4870 1GB vs Radeon HD 4870 2GB
Intro
The Radeon HD 4870 1GB comes with core speeds of 750 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.Compare all that to the Radeon HD 4870 2GB, which has core clock speeds of 750 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR5 RAM. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Both cards have the same power consumption.Memory Bandwidth
Both cards have exactly the same memory bandwidth, so in theory they should perform exactly the same. (explain)
Texel Rate
Both cards have exactly the same texel fill rate, so in theory they should perform equally good at at anisotropic filtering. (explain)Pixel Rate
Both cards have exactly the same pixel fill rate, so in theory they should be equally good at at AA, and be capable of handling the same screen resolutions. (explain)
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
Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.
Radeon HD 4870 1GBAmazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
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Radeon HD 4870 2GBAmazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
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Specifications
| Model | Radeon HD 4870 1GB | Radeon HD 4870 2GB |
|---|---|---|
| Manufacturer | ATi | ATi |
| Year | Jun 25, 2008 | Jun 25, 2008 |
| Code Name | RV770 XT | RV770 XT |
| Fab Process | 55 nm | 55 nm |
| Bus | PCIe 2.0 x16 | PCIe 2.0 x16 |
| Memory | 1024 MB | 2048 MB |
| Core Speed | 750 MHz | 750 MHz |
| Shader Speed | N/A MHz | (N/A) MHz |
| Memory Speed | 900 MHz | 900 MHz |
| Unified Shaders | 800(160x5) | 800(160x5) |
| Texture Mapping Units | 40 | 40 |
| Render Output Units | 16 | 16 |
| Bus Type | GDDR5 | GDDR5 |
| Bus Width | 256-bit | 256-bit |
| DirectX Version | DirectX 10.1 | DirectX 10.1 |
| OpenGL Version | OpenGL 3.0 | OpenGL 3.0 |
| Power (Max TDP) | 150 watts | 150 watts |
| Shader Model | 4.1 | 4.1 |
| Bandwidth | 115200 MB/sec | 115200 MB/sec |
| Texel Rate | 30000 Mtexels/sec | 30000 Mtexels/sec |
| Pixel Rate | 12000 Mpixels/sec | 12000 Mpixels/sec |
Memory Bandwidth: Bandwidth is the max amount of data (in units of MB per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, 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 texture map elements (texels) that can be processed per second. This is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, 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 number of pixels that the graphics chip could possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.
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