ICH1 - ATA/66, 1 controller and 2 USB 1.1, No LAN, Audio/Modem, SMBus
ICH2 - ATA/100,  2 controllers and 4 USB, 10/100 LAN, Audio/Modem
ICH4 - ATA/100, 6 ports USB 2.0, 10/100 LAN, Enhance 20bit Audio, SMBus 2.0
ICH5 - 2 SATA  150, RAID, LAN, 8 ports USB 2.0, AC'97 Audio, SMBus 2.0

ICH6 - 4 SATA 150 & UDMA ATA100, LAN, 8 ports USB 2.0, High Def Intel Audio, SMBus 2.0
ICH6R - IMS, RAID 0 & 1
ICH6-M - Mobile version, no RAID support.

ICH7 - 4 SATA 300 & 1 PATA, PCI Express, 8 ports USB 2.0, High Def Intel Audio, 10/100
ICH7R - PCI Express x1 6 slots, IMS, RAID 0, 1, 5, and 10
ICH7DE - PCI Express x1 6 slots, IMS, RAID 0, 1, 5, and 10, AMT
ICH7DO - PCI Express x1 4 slots, IMS, No RAID, AMT
ICH7DH - PCI Express x1 6 slots, IMS, RAID 0, 1, and 10, EnergyLake

  
ICH8 - 6 SATA 300  & eSATA, PCI Exprerss, 10 Ports USB 2.0, High Def Intel Audio or AC'97, No RAID, Gigabit
ICH8R - PCI Express x1 4 slots, IMS2, RAID 0, 1, 5, 10
ICH8DH - PCI Express x1 4 slots, IMS2, RAID 0, 1, 5, 10, Quick Resume
ICH8DO - PCI Express x1 4 slots, IMS2, RAID 0, 1, 5, 10, AMT


AMT - Advanced Management Technology - a new level of active control and enterprise resource management.
EnergyLake - Power saving features
QRT - Quick Resume Technology - Instant On/Off for PC
R - RAID
DH - Digital Home
DO - Digital Office
DE - Digital Enterprise
IMS - Intel Matrix Storage