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PERC 2/DC Features •
PERC 2/DC Block Diagram
The Dell™ PowerEdge™ Expandable RAID Controller 2/Dual Channel (PERC 2/DC) PCI RAID controller is a high performance intelligent Peripheral Component Interconnect (PCI)-to-Small Computer System Interface (SCSI) host adapter with RAID control capabilities. The PERC 2/DC provides reliability, high performance, and fault-tolerant disk subsystem management. PERC 2/DC is an ideal RAID solution for the internal strorage of Dell's workgroup, departmental, and enterprise systems. PERC 2/DC offers a cost-effective way to implement RAID in a server. PERC 2/DC has two Wide Ultra2 Low Voltage Differential (LVD) SCSI channels supporting data transfer rates up to 80 Megabytes per second (MB/s) per channel.
The PERC 2/DC features include:
- Wide Ultra2 LVD SCSI performance of up to 80MB/s
- 64MB or 128MB of Synchronous Dynamic Random Access Memory (SDRAM)
- 64-bit PCI host interface
- On-board i960RN processor to improve controller performance and offload host Central Processing Unit (CPU)
- Two internal and external connectors
- RAID levels 0 (striping), 1 (mirroring), 5 (distributed parity), 10 (combination of striping and mirroring), and 50 (combination of striping and distributed parity)
- Advanced array configuration and management utilities
- Up to 12 SCSI drives per channel using the Dell PowerVault 21xS storage system
SCSI Channel
The PERC 2/DC controller card includes two SCSI channels. Each channel is powered by a Symbios Logic/LSI 53C896 SCSI processor.
Non-volatile Random Access Memory (NVRAM) and Flash Read-only Memory (ROM)
A 32 KB x 8 NVRAM stores RAID system configuration information. The PERC 2/DC firmware is stored in flash ROM for easy upgrade.
SCSI Connectors
PERC 2/DC has two ultra high density 68-pin external connectors for the external storage subsystem, and two high density 68-pin internal connectors.
Single Ended and Differential SCSI Buses
The SCSI standard defines two electrical buses: a single ended bus and low-voltage differential bus. PERC 2/DC supports both standards.
Maximum Cable Length for SCSI Standards
Table 1. Maximum Cable Length for SCSI Standards
|
SCSI Standard |
Single ended |
LVD |
Maximum Number of Drives |
|
SCSI I |
6 m |
12 m |
7 |
|
Fast SCSI |
6 m |
12 m |
7 |
|
Fast Wide SCSI |
6 m |
12 m |
12 |
|
Ultra SCSI |
1.5 m |
12 m |
7 |
|
Ultra SCSI |
3 m |
12 m |
3 |
|
Wide Ultra SCSI |
|
12 m |
12 |
|
Wide Ultra SCSI |
1.5 m |
12 m |
7 |
|
Wide Ultra SCSI |
3 m |
12 m |
3 |
|
Ultra 2 SCSI |
|
25 m |
1 |
|
Ultra 2 SCSI |
|
12 m |
7 |
|
Wide Ultra 2 SCSI |
|
25 m |
1 |
|
Wide Ultra 2 SCSI |
|
12 m |
7 |
