Dell PowerEdge R330 Owner's Manual page 55

Figure 17. Inside the system—with eight 2.5-inch hard drives
1. optical drive (optional)
3. power interposer board
5. expansion card riser
7. processor
9. cooling fan (4)
11. hard drive (8)
2. hard drive backplane
4. power supply unit (2)
6. memory module socket (4)
8. system board
10. intrusion switch
12. control panel assembly
55