Dell OptiPlex 790 Owner's Manual page 89

System Board Connectors
PCI 2.3 data width (maximum) — 32 bits
Mini-Tower, Desktop
Small Form Factor, Ultra Small Form
Factor
PCI Express x1 data width (maximum) — one PCI Express lane
Mini-Tower, Desktop, Small Form
Factor
Ultra Small Form Factor
PCI Express x16 (wired as x4) data width (maximum) — four PCI Express lanes
Mini-Tower, Desktop, Small Form
Factor
Ultra Small Form Factor
PCI Express x16 data width (maximum) — 16 PCI Express lanes
Mini-Tower, Desktop, Small Form
Factor
Ultra Small Form Factor
Serial ATA
Mini-Tower
Desktop, Small Form Factor
Ultra Small Form Factor
Memory
Mini-Tower, Desktop, Small Form
Factor
Ultra Small Form Factor
Internal USB
Mini-Tower, Desktop
Small Form Factor, Ultra Small Form
Factor
System Fan
one 120-pin connector
none
one 164-pin connector
none
one 164-pin connector
none
one 164-pin connector
none
four 7-pin connectors
three 7-pin connectors
two 7-pin connectors
four 240-pin connectors
two 240-pin connectors
one 10-pin connector
none
one 5-pin connector
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