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Radeon HD 3850 512MB vs Radeon HD 4850 2GB
Intro
The Radeon HD 3850 512MB uses a 55 nm design. ATi has clocked the core speed at 668 MHz. The GDDR3 memory runs at a frequency of 828 MHz on this particular model. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 ROPs.Compare those specs to the Radeon HD 4850 2GB, which features core clock speeds of 625 MHz on the GPU, and 993 MHz on the 2048 MB of GDDR4 RAM. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
| Radeon HD 3850 512MB |
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75 Watts |
| Radeon HD 4850 2GB |
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110 Watts |
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Memory Bandwidth
As far as performance goes, the Radeon HD 4850 2GB should theoretically be just a bit better than the Radeon HD 3850 512MB overall. (explain)
| Radeon HD 4850 2GB |
|
63552 MB/sec |
| Radeon HD 3850 512MB |
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52992 MB/sec |
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Texel Rate
The Radeon HD 4850 2GB will be quite a bit (more or less 134%) faster with regards to anisotropic filtering than the Radeon HD 3850 512MB. (explain)| Radeon HD 4850 2GB |
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25000 Mtexels/sec |
| Radeon HD 3850 512MB |
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10688 Mtexels/sec |
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Pixel Rate
If using lots of anti-aliasing is important to you, then the Radeon HD 3850 512MB is a better choice, not by a very large margin though. (explain)| Radeon HD 3850 512MB |
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10688 Mpixels/sec |
| Radeon HD 4850 2GB |
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10000 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
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 3850 512MBAmazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
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Radeon HD 4850 2GBAmazon.com
Other US-based stores
Amazon.co.uk
Amazon.de
Amazon.fr
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Specifications
| Model | Radeon HD 3850 512MB | Radeon HD 4850 2GB |
|---|---|---|
| Manufacturer | ATi | ATi |
| Year | Nov 19, 2007 | Jun 25, 2008 |
| Code Name | RV670 PRO | RV770 PRO |
| Fab Process | 55 nm | 55 nm |
| Bus | PCIe 2.0 x16/AGP 8x | PCIe 2.0 x16 |
| Memory | 512 MB | 2048 MB |
| Core Speed | 668 MHz | 625 MHz |
| Shader Speed | N/A MHz | (N/A) MHz |
| Memory Speed | 828 MHz | 993 MHz |
| Unified Shaders | 320(64x5) | 800(160x5) |
| Texture Mapping Units | 16 | 40 |
| Render Output Units | 16 | 16 |
| Bus Type | GDDR3 | GDDR4 |
| 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) | 75 watts | 110 watts |
| Shader Model | 4.1 | 4.1 |
| Bandwidth | 52992 MB/sec | 63552 MB/sec |
| Texel Rate | 10688 Mtexels/sec | 25000 Mtexels/sec |
| Pixel Rate | 10688 Mpixels/sec | 10000 Mpixels/sec |
Memory Bandwidth: Memory bandwidth is the max amount of information (in units of MB per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 applied in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.
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