| Number of Hard Drives by Model at Backblaze 
 | 
| Model | Size | Numberof Drives
 | Average Agein years
 | Annual Failure Rate | 
| Seagate Desktop HDD.15 (ST4000DM000)
 | 4.0TB | 9619 | 0.6 | 3.0% | 
| HGST Deskstar 7K2000 (HGST HDS722020ALA330)
 | 2.0TB | 4706 | 3.4 | 1.1% | 
| HGST Deskstar 5K3000 (HGST HDS5C3030ALA630)
 | 3.0TB | 4593 | 2.1 | 0.7% | 
| Seagate Barracuda 7200.14 (ST3000DM001)
 | 3.0TB | 3846 | 1.9 | 15.7% | 
| HGST Megascale 4000.B (HGST HMS5C4040BLE640)
 | 4.0TB | 2884 | 0.2 | n/a | 
| HGST Deskstar 5K4000 (HGST HDS5C4040ALE630)
 | 4.0TB | 2627 | 1.2 | 1.2% | 
| Seagate Barracuda LP (ST31500541AS)
 | 1.5TB | 1699 | 4.3 | 9.6% | 
| HGST Megascale 4000 (HGST HMS5C4040ALE640)
 | 4.0TB | 1305 | 0.1 | n/a | 
| HGST Deskstar 7K3000 (HGST HDS723030ALA640)
 | 3.0TB | 1022 | 2.6 | 1.4% | 
| Western Digital Red (WDC WD30EFRX)
 | 3.0TB | 776 | 0.5 | 8.8% | 
| Western Digital Caviar Green (WDC WD10EADS)
 | 1.0TB | 476 | 4.6 | 3.8% | 
| Seagate Barracuda 7200.11 (ST31500341AS)
 | 1.5TB | 365 | 4.3 | 24.9% | 
| Seagate Barracuda XT (ST33000651AS)
 | 3.0TB | 318 | 2.2 | 6.7% |