Dell XPS 730 (Late 2008) - Manual (Page 11)

Technical Overview 11
1 CPU socket 2 system board CPU fan header
3 DIMMs 1, 3, and 5 4 ATX power connector
(ATX_PWR)
5 IDE connector (IDE) 6 SATA port 4 (SATA 4)
7 battery socket 8 SATA ports 1-3 (SATA 1-3)
9 internal USB header 1 (USB) 10 internal USB header 2 (USB)
11 internal USB header 3 (USB) 12 1394 header
13 PCI slot 1 (PCI SLOT 1) 14 front panel audio header (FP
Audio)
15 PCIe slot 5 (PCI_E5) 16 PCIe slot 4 (PCI_E4)
17 PCIe slot 3 (PCI_E3) 18 PCIe slot 2 (PCI_E2)
19 PCIe slot 1 (PCI_E1) 20 CPU power header