Over view 25• Two internal and four external connectors for the PERC 3/QC, twointernal and two external connectors for the PERC 3/DC and PERC3/DCL, and one internal and one external connector for the PERC3/SC• RAID levels 0 (striping), 1 (mirroring), 5 (distributed parity), 10(combination of striping and mirroring), and 50 (combination ofstriping and distributed parity)• Advanced array configuration and management utilities• Battery backup for up to 72 hours for the PERC 3/QC and PERC3/DCNOTE: Clustering is notsupported by PERC 3/QCor PERC 3/DCL.• Up to 12 SCSI drives per channel using the Dell PowerVault 21xSstorage system or 14 SCSI drives using the Dell PowerVault 22xSSCSI ChannelsThe PERC 3/QC controller card includes four SCSI channels. There are twoQLogic ®12160 chips; each chip controls two SCSI channels.The PERC 3/DC and PERC 3/DCL controller cards include two SCSIchannels. There is one QLogic 12160 chip, which controls two SCSIchannels.The PERC 3/SC controller card has one SCSI channel. There is one QLogic10160 chip.Non-volatile Random Access Memory (NVRAM) and Flash Read-only Memory (ROM)A 32 KB x 8 NVRAM stores RAID system configuration information. ThePERC 3 firmware is stored in flash ROM for easy upgrade.SCSI ConnectorsPERC 3/QC has four ultra-high-density 68-pin external connectors for theexternal storage subsystem and two high-density 68-pin internal connectors.PERC 3/DC and PERC 3/DCL have two ultra-high-density 68-pin externalconnectors for the external storage subsystem and two high-density 68-pininternal connectors.
