Asus M2N-LR/SATA - Manual (Page 35)

2- Chapter 2: Hardware information
2.5.5 PCI slot
The PCI slot supports cards such as a LAN
card, SCSI card, USB card, and other cards
that comply with PCI specifications. The
figure shows a LAN card installed on a PCI
slot.
• Important note on M2N-LR:
When one PCI-X slot is populated, the PCI-X frequency is 133MHz. When
both PCI-X slots are populated, the PCI-X frequency is 100MHz. Refer to
table below for details.
• Important note on M2N-LR/SATA:
When one PCI-X slot is populated, the PCI-X frequency is 100MHz. When
both PCI-X slots are populated, the PCI-X frequency is 66MHz. Refer to
table below for details.
PCI-X Frequency
M2N-LR M2N-LR/SATA
PCI-X
 slot
(PCIX)
PCI-X
2 slot
(PCIX2)
Frequency PCI-X
 slot
(PCIX)
PCI-X
2 slot
(PCIX2)
Frequency
populated -- 133MHz populated -- 100MHz
-- populated 133MHz -- populated 100MHz
populated populated 100MHz populated populated 66MHz
2.5.6 ZCR slot ( M2N-LR/SATA model only)
The 64-bit PCI-X slot (green) on the motherboard supports a Zero-Channel RAID
card that allows RAID0, RAID1, RAID10, RAID5, and JBOD configurations.