Dell 400 Owner's Manual page 112

Expansion Bus
Bus type
Bus speed
Bus throughput
PCI
connectors
connector size
connector data width (maximum)
PCI Express
connector
connector size
connector data width (maximum)
PCI Express
connector
connector size
connector data width (maximum)
PCI Express
connector
connector size
connector data width (maximum)
112
Appendix
PCI 32 bit
PCI Express x1, x4, and x16
PCI: 33 MHz
PCI Express:100 MHz
PCI Express:
x1 slot bidirectional speed - 500 MB/s
x4 slot bidirectional speed - 2 GB/s
x16 slot bidirectional speed - 8 GB/s
three
120 pins
32 bits
one x1
36 pins
1 PCI Express lane
one x4
98 pins
4 PCI Express lanes
one x16
164 pins
16 PCI Express lanes