Intel SRCU32 - RAID Controller, User Manual

Page: 27 / 182

Getting Started 27
Table 3. RAID Level, Hard Drives, and Usable Storage Capacity
RAID Level
Available
Capacity with
2 Hard Drives* Available
Capacity with
3 Hard Drives* Available
Capacity with
4 Hard Drives*
Available
Capacity with
5 Hard Drives*
RAID 0 2 GB 3 GB 4 GB 5 GB
RAID 1 1 GB 1 GB 1 GB 1 GB
RAID 4 NA 2 GB 3 GB 4 GB
RAID 5 NA 2 GB 3 GB 4 GB
RAID 10 NA NA 2 GB NA
* Each hard drive is assumed to have 1 GB capacity.
Are Hot Fix Drives Needed?
Assume that one of the hard drives of the RAID 5 disk array fails (Hot Fix drives are available with
RAID 1, 4, 5, and 10 arrays). The disk array is without redundancy. Time Without Redundancy
(TWR) starts to run. Any unnecessary prolongation of the TWR (the time required to get a
replacement drive, or because you did not immediately recognize the failure) increases the risk of
data loss that will occur should a second drive fail. Therefore, redundancy should be restored as
soon as possible and in an automated manner. Integrating a Hot Fix drive (also referred to as hot
spare) as an immediately available and auto-replacing drive is the most effective way to keep the
TWR as short as possible. Only a Hot Fix drive can ensure optimal disk array security and constant
data availability.
Using a Hot Fix drive is not compulsory. If you control the disk array at regular intervals and
immediately replace a defective drive (by shutting down the system or hot-plugging), you can
operate the system without a Hot Fix drive.
Intel RAID Controller Hardware Features
This section provides a summary of the key features, configuration options and support interface
technology supported by the IIR controller.
Architecture Features (HW)
Table 4. Hardware Architecture
Component Feature
I/O Microprocessor The 80303 uses the 100MHz Intel 80960JT-100 core with a
100MHz/64-bit internal bus
with an internal throughput of up to
800MB/sec,
to and from the internal IOP peripherals.
Cache Memory The SRCU32 supports up to 256MB of 64-bit ECC SDRAM
operating at 100MHz. Memory is expandable to 64, 128, or 256MB.
Flash Memory 3.3v, 16Mb (2MB) flash memory chip is used to store the RAID
firmware
I/O interface (PCI) PCI 2.2 compliant, universally keyed for 3.3 and 5 volt PCI slots
PCI Transfer Rate 528MB/sec (Burst)
PCI Signaling 5 or 3.3 volt
SCSI Controller: LSI SYM53C1010 Dual channel Ultra160