Dell TD977 / X6847 PERC 4e/DC SCSI RAID Controller

RAID levels

0, 1, 5, 10, and 50

0, 1, 5, 10, and 50

0, 1, 5, 10, and 50

SCSI channels

1

2

2

Array interface to host

PCI Rev 2.2

PCI Rev 2.2

PCI Express Rev. 1.0a

Storage interface

SCSI U320

SCSI U320

SCSI U320

Cache memory size

64 MB SDRAM

128 MB SDRAM

128 MB DDR SDRAM

Cache function

Write-back, write-through, adaptive read-ahead, non read-ahead, read-ahead

Write-back, write-through, adaptive read-ahead, non read-ahead, read-ahead

Write-back, write-through, adaptive read-ahead, non read-ahead, read-ahead

Cache battery backup

No

Yes

Yes

Number of logical drives and arrays supported

Up to 40 logical drives and 32 arrays per controller

Up to 40 logical drives and 32 arrays per controller

Up to 40 logical drives and 32 arrays per controller

Maximum logical drive size supported

2 TB for all RAID levels (0, 1, 5, 10, and 50)

2 TB for all RAID levels (0, 1, 5, 10, and 50)

2 TB for all RAID levels (0, 1, 5, 10, and 50)

Online capacity expansion

Yes

Yes

Yes

Hot spares

Yes

Yes

Yes

Flashable firmware

Yes

Yes

Yes

Hot swap devices supported1

Yes

Yes

Yes

Non-disk devices supported

NOTE: PERC 4 does not support any non-disk devices except backplanes.

Only SAF-TE2

and SES3

Only SAF-TE

and SES

Only SAF-TE

and SES

Mixed capacity hard drives

Yes

Yes

Yes

Number of 16-bit internal connectors

1

2

2

Number of 16-bit external connectors

1

2

2

Cluster support

No

Yes

Yes