| Attribute | Radeon HD 4855 × | Radeon HD 6750M Mac × |
|---|---|---|
| GPU | ||
| Release year (year) | 2010 | 2011 |
| Reference card | ATi Radeon HD 4855 575 MHz 512 MB | - |
| GPU brand | ATI | AMD |
| GPU name | RV770 | Whistler |
| Market | Desktop | Laptop |
| Clock speed (MHz) | 575 | 598 |
| Is dual GPU | - | - |
| Model | Radeon HD 4855 | Radeon HD 6750M Mac |
| Memory | ||
| Memory (MB) | 512 | 512 |
| Memory bandwidth (GB/s) | 115.2 | 50.8 |
| Memory bus (bit) | 256 | 128 |
| Memory type | GDDR5 | GDDR5 |
| Memory clock speed (MHz) | 900 | 794 |
| Effective memory clock speed (MHz) | 3,600 | 3,176 |
| Noise and power | ||
| TDP (W) | 110 | 35 |
| Raw performance | ||
| Pixel rate (GPixel/s) | 9.2 | 4.78 |
| Render output processors | 16 | 8 |
| Texture mapping units | 32 | 24 |
| Shading units | 640 | 480 |
| Floating-point performance (GFLOPS) | 736 | 574 |
| Compute units | 8 | 6 |
| Texture rate (GTexel/s) | 18.4 | 14.35 |