Storage Matrix; Redundant Array Of Independent Disks (Raid) - Dell OptiPlex Small Form Factor 7020 Owner's Manual

Table 12. Storage specifications (continued)
Storage type
M.2 2230 solid-state drive, Class 35,
Self-Encrypting drive
M.2 2280 solid-state drive, Class 40
M.2 2280 solid-state drive, Class 40,
Self-Encrypting drive

Storage matrix

The following table lists the storage configurations supported on your OptiPlex Small Form Factor 7020.
Table 13. Storage matrix
Storage
One M.2 2230/2280 solid-state drive
One M.2 2230/2280 solid-state drive
+
One 3.5-inch hard-disk drive
One M.2 2230/2280 solid-state drive
+
One M.2 2230/2280 solid-state drive (via PCIe Expansion card)
One M.2 2230/2280 solid-state drive
+
One 3.5-inch hard-disk drive
+
One M.2 2230/2280 solid-state drive (via PCIe Expansion card)

Redundant Array of Independent Disks (RAID)

For optimal performance when configuring drives as a RAID volume, Dell Technologies recommends drive models that are
identical.
NOTE: RAID is not supported on Intel Optane configurations.
RAID 0 (Striped, Performance) volumes benefit from higher performance when drives are matched because the data is split
across multiple drives: any I/O operations with block sizes larger than the stripe size splits the I/O and become constrained by
the slowest of the drives. For RAID 0 I/O operations where block sizes are smaller than the stripe size, whichever drive the I/O
operation targets, determines the performance, which increases variability and results in inconsistent latencies. This variability
is particularly pronounced for write operations, and it can be problematic for applications that are latency sensitive. One such
example of this is any application that performs thousands of random writes per second in very small block sizes.
RAID 1 (Mirrored, Data Protection) volumes benefit from higher performance when drives are matched because the data
is mirrored across multiple drives all I/O operations must be performed identically to both drives, thus variations in drive
performance when the models are different result in the I/O operations completing only as fast as the slowest drive. While this
does not suffer from the variable latency issue in small random I/O operations as with RAID 0 across heterogeneous drives, the
impact is nonetheless large because the higher performing drive becomes limited in all I/O types. One of the worst examples
24 Specifications of OptiPlex Small Form Factor 7020
Interface type
PCIe NVMe, up to 32 Gbps
PCIe NVMe, up to 32 Gbps
PCIe NVMe, up to 32 Gbps
Slot
SSD0 (Primary
M.2 PCIe for
boot function)
Yes
Yes
Yes
Yes
Restricted - Confidential
Capacity
256 GB
Up to 1 TB
Up to 1 TB
SLOT1 (PCIe x1 SATA0
slot)
Yes
Yes
Yes Yes