Dell PowerEdge R420 Quick start guide

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May 2012 | Rev 1.0

Table of contents
1System overview..................................................................................................................................................................5
Introduction.........................................................................................................................................................................5
New technologies ............................................................................................................................................................. 6
2System features ...................................................................................................................................................................7
Comparison of PowerEdge systems ...............................................................................................................................7
Specifications ..................................................................................................................................................................... 8
3Chassis views and features ............................................................................................................................................. 10
Chassis views.................................................................................................................................................................... 10
Chassis features ................................................................................................................................................................ 11
4Processor............................................................................................................................................................................14
Processor features............................................................................................................................................................14
Supported processors......................................................................................................................................................14
Chipset................................................................................................................................................................................15
5Memory...............................................................................................................................................................................16
Supported memory ..........................................................................................................................................................16
Memory configurations ...................................................................................................................................................17
Memory speed ..................................................................................................................................................................18
Memory RAS features.......................................................................................................................................................18
6Storage ............................................................................................................................................................................... 20
Internal storage ................................................................................................................................................................ 20
External storage ................................................................................................................................................................21
Storage controllers...........................................................................................................................................................21
Optical drive ..................................................................................................................................................................... 23
Tape drive.......................................................................................................................................................................... 23
7Networking and PCIe ...................................................................................................................................................... 24
Embedded NIC controller.............................................................................................................................................. 24
PCIe expansion ................................................................................................................................................................ 24
8Power, thermal, and acoustics ...................................................................................................................................... 26
Power consumption and energy efficiency................................................................................................................ 26
Power supply units .......................................................................................................................................................... 27
Thermal and acoustics.................................................................................................................................................... 28
9Rack rails and cable management .................................................................................................................................31
Sliding and static rail systems .........................................................................................................................................31
Cable management arm................................................................................................................................................. 33
10 Operating systems and virtualization ........................................................................................................................... 34
Supported operating systems........................................................................................................................................ 34
Supported virtualization ................................................................................................................................................. 35
11 Dell OpenManage systems management.................................................................................................................... 36
Systems management solutions ................................................................................................................................... 36
OpenManage systems management ........................................................................................................................... 37
Dell server management operations............................................................................................................................ 42
Additional specifications.......................................................................................................................... 44Appendix A.
Chassis dimensions and weight ....................................................................................................................................44
Power supply specifications ..........................................................................................................................................44
Environmental specifications ........................................................................................................................................ 45
Video specifications ........................................................................................................................................................ 46
Rack rail specifications ................................................................................................................................................... 46
USB peripherals................................................................................................................................................................ 46
Standards compliance ............................................................................................................................. 47Appendix B.

Additional resources.................................................................................................................................48Appendix C.
Table 1. New technologies ................................................................................................................................................ 6
Table 2. Comparing the PowerEdge R410 to PowerEdge R420 .................................................................................7
Table 3. Technical specifications...................................................................................................................................... 8
Table 4. Chassis features................................................................................................................................................... 11
Table 5. Security features..................................................................................................................................................13
Table 6. Supported processors ........................................................................................................................................15
Table 7. Memory technologies supported.....................................................................................................................16
Table 8. DIMMs supported................................................................................................................................................17
Table 9. Memory speed capabilities ................................................................................................................................18
Table 10. Memory RAS features .........................................................................................................................................18
Table 11. Supported hard drives ....................................................................................................................................... 20
Table 12. Supported RAID controllers...............................................................................................................................21
Table 13. Hard-drive backplane options ......................................................................................................................... 22
Table 14. PCIe slot configurations.................................................................................................................................... 24
Table 15. Supported NICs and HBAs................................................................................................................................ 25
Table 16. Power tools and technologies ......................................................................................................................... 26
Table 17. Power supply efficiency .................................................................................................................................... 28
Table 18. Acoustical performance.................................................................................................................................... 30
Table 19. Supported rack types......................................................................................................................................... 32
Table 20. Primary operating system support .................................................................................................................. 34
Table 21. Virtualization support ........................................................................................................................................ 35
Table 22. iDRAC7 with Lifecycle Controller functions and benefits........................................................................... 37
Table 23. Feature comparison for basic management, iDRAC7 Express, and iDRAC7 Enterprise....................... 38
Table 24. One-to-one and one-to-many operations .................................................................................................. 43
Table 25. Power supply specifications............................................................................................................................. 44
Table 26. Environmental specifications ........................................................................................................................... 45
Table 27. Supported video modes....................................................................................................................................46
Table 28. Rail adjustability range....................................................................................................................................... 46
Table 29. Industry standard documents .......................................................................................................................... 47
Table 30. Additional resources ..........................................................................................................................................48
Figure 1. Front view without bezel .................................................................................................................................. 10
Figure 2. Front view with bezel......................................................................................................................................... 10
Figure 3. Back view ............................................................................................................................................................. 10
Figure 4. Internal view ......................................................................................................................................................... 11
Figure 5. LCD control panel...............................................................................................................................................12
Figure 6. QRL location ........................................................................................................................................................12
Figure 7. 550W power supply unit ................................................................................................................................... 28
Figure 8. Sliding rails with optional CMA .........................................................................................................................31
Figure 9. Static rails............................................................................................................................................................. 32
Figure 10. Dell systems management solutions.............................................................................................................. 36
Figure 11. Systems management server lifecycle ........................................................................................................... 42
Figure 12. System dimensions ............................................................................................................................................44

The Dell™ PowerEdge™ R420 is a 2-socket, 1U rack-mount server offering powerful performance
and scalability in a dense 1U rack form factor. It is an excellent fit for compute-intense applications
and high performance computing (HPC) workloads. The R420’s low profile also makes it highly
attractive for departmental email, workgroup collaboration, and file and print in space-constrained
environments at departmental or remote sites of large businesses and public organizations.
The R420 features the extensive performance of two Intel®Xeon®E5-2400 processors. Powerful
processors alone, however, are not enough to deliver balanced performance. Compute power must
be combined with sufficient memory and I/O bandwidth to prevent performance bottlenecking. The
R420 complements its processors with 12 DIMM slots and two PCI Express®(PCIe) 3.0-enabled
I/O slots, providing a substantial memory footprint and wide I/O bandwidth to support both
memory-intensive and data-intensive applications and databases. These combined technology
features are also key design requirements when supporting consolidated and virtualized
environments, a role the R420 fits well. To protect your virtualized workloads, the R420 offers dual,
redundant SD media making your hypervisors redundant and failsafe. Other reliability and availability
features include up to four 3.5-inch or eight 2.5-inch hot-plug hard drives, both hardware and
software RAID options, and redundant, hot-plug power supplies.
The PowerEdge family is engineered with the right combination of features and performance
scalability to handle tough workloads for both large and small data center environments.
The Dell OpenManage™ systems management portfolio includes Integrated Dell Remote Access
Controller 7 (iDRAC7) with Lifecycle Controller. This embedded feature helps IT administrators
manage Dell servers in physical, virtual, local and remote environments, operating in-band or
out-of-band, with or without a systems management software agent. OpenManage also integrates
and connects to third-party systems management solutions so you can maintain your single point of
control and capitalize on your existing investment. OpenManage simplifies the lifecycle of
deploying, updating, monitoring, and maintaining your Dell PowerEdge servers.

Table 1 summarizes the newest technologies used in the Dell PowerEdge R420 rack server.
New technologies
Detailed descriptions
Intel Xeon processor
E5-2400 product family
This new family of Intel processors has embedded PCIe lanes for improved I/O
performance. See the Processor section for details.
Intel C600 series chipset
The Intel Platform Controller Hub (PCH) chip is implemented on the R420 server.
1600 MT/s DDR3
memory
Certain models of the E5-2400 series processors support 1600 MT/s memory. The
R420 supports two DIMMs per channel at 1600 MT/s with certain models. See the
Memory section for details.
Next generation PERC
options
The R420 supports the new PERC controller cards with improved functionality and
faster performance. See the Storage section for details.
PERC S110 software
RAID Solution
This new software RAID solution supports RAID 0, 1, 5 and 10, and supports a
maximum of four hot-plug SATA hard drives or SATA solid-state drives. See the
Storage section for details.
iDRAC7 with Lifecycle
Controller
The new embedded system management solution for Dell servers features
hardware and firmware inventory and alerting, in-depth memory alerting, faster
performance, a dedicated gigabit port, and many more features. See the Dell
OpenManage systems management section for details.
Advanced power
management
The R420 supports advanced power monitoring and power capping tools that can
help manage power consumption. See the Power, thermal, and acoustics section
for details.
Fresh Air cooling
Dell has tested and validated an integrated data center solution that enables you
to operate at higher temperatures or even chiller-less. See the Power, thermal, and
acoustics section for details.
Failsafe hypervisors
The internal dual SD module is a modular fail-safe design that is dedicated for an
embedded ESX hypervisor or other embedded operating system. See the
Supported virtualization for details.
Fan fault tolerance
Failure of one fan rotor is tolerated with degradation in performance through
active throttling and increased fan speeds. The feature helps reduce downtime by
allowing you to schedule a fan replacement within 360 hours of a fan failure.

Compared to the previous generation of Dell PowerEdge servers, the R420 supports more PCIe
slots, PCIe 3.0, more memory, and advanced system management. Table 2 compares some of the
features of the R420 to its R410 predecessor. Table 3 lists all of the R420’s specifications.
The R420 is the new generation PowerEdge server replacing the R410.
Feature
PowerEdge R410
PowerEdge R420
Chassis
1U rack
1U rack
Processors
IntelXeonprocessors 5500 and 5600
series
Intel Xeon processor E5-2400 product
family
Internal interconnect
Intel QuickPath Interconnect
Intel QuickPath Interconnect
Memory1
8 x DDR3 RDIMM and UDIMM
Up to 128GB
12 x DDR3 RDIMM and UDIMM
Up to 192GB
Hard drive bays
(hot-plug)
Up to 4 x 3.5” cabled or hot-plug
Up to 4 x 3.5” cabled or hot-plug
Up to 8 x 2.5” hot-plug
RAID controller
PERC H200, H700, H800
PERC H310, H710, H710P, H810, S110
PCI slots
1 PCIe 2.0 slots
2 PCIe 3.0 slots
Embedded NIC
Dual Port 1GbE LOM
Dual Port 1GbE LOM
Power supplies
Non-redundant 480W
Redundant 500W
Non-redundant 550W
Redundant 350W or 550W
Systems management
Dell OpenManage
Dell Management Console
Lifecycle Controller 1.x
Dell OpenManage Essentials
Dell Management Console
OpenManage Power Center (requires
iDRAC7 Enterprise with Lifecycle
Controller 2.x)
Remote management
Baseboard Management Controller
iDRAC6 (Express or Enterprise) with
Lifecycle Controller 1.x
Basic management upgradeable to
iDRAC7 (Express or Enterprise) with
Lifecycle Controller 2.x
Power efficiency
Gold
Platinum
Availability
Hot-plug drives
Hot-plug redundant power supply units
Hot-plug drives
Hot-plug redundant power supply units
Fan fault tolerance
Fault resilient memory
Internal dual SD module
1GB means 1 billion bytes and TB equals 1 trillion bytes; actual capacity varies with preloaded material and operating
environment and will be less.

Table 3 summarizes the specifications for each of the PowerEdge R420 features. For the latest
information on supported features for the PowerEdge R420, visit Dell.com.
Feature
PowerEdge R420 technical specification
Form factor
1U rack
Processors
Intel Xeon processor E5-2400 product family
Processor sockets
2
Internal interconnect
Intel QuickPath Interconnect (QPI) link: 6.4 GT/s, 7.2 GT/s, 8.0 GT/s
Cache
2.5MB per core with core options of 4, 6, or 8
Chipset
Intel C600
Memory1
Up to 192GB (12 DIMM slots): 2GB/4GB/8GB/16GB DDR3 up to 1600 MT/s
PCIe slots
2 PCIe slots
With 2 processors:
1 x16 slot with x16 bandwidth, 3.0, half-height, half-length
1 x16 slot with x16 bandwidth, 3.0, full-height, half-length
With 1 processor:
1 x8 slot with x4 bandwidth, 2.0, half-height, half-length
1 x16 slot with x16 bandwidth, 3.0, full-height, half-length
RAID controller
Internal controllers:
PERC S110 (SW RAID)
PERC H310
PERC H710
PERC H710P
External HBAs (RAID):
PERC H810
External HBAs (non-RAID):
6Gbps SAS HBA
Hard drives
Drive bay options:
4 x 3.5” cabled drive bays or
4 x 3.5” hot-plug drive bays (2.5”hybrid kit available) or
8 x 2.5” hot- plug drive bays
Hot-plug hard drive options:
2.5” SATA, nearline SAS, SAS (15K, 10K), SAS SSD, SATA SSD
3.5” SATA, nearline SAS, SAS (15K)
Self-encrypting drives available
Cabled hard drive options:
3.5” SATA, nearline SAS, SAS (15K)
Embedded NIC
Broadcom®5720 GbE Dual Port
Power supply
Platinum efficiency 550W and 350W power supplies
Silver efficiency cabled 550W power supply
Auto-ranging power supplies

Feature
PowerEdge R420 technical specification
Availability
High-efficiency, hot-plug, redundant power supplies; hot-plug hard drives; TPM;
dual internal SD support; fan fault tolerance; optional bezel; information tag; ECC
memory; interactive LCD screen; extended power range; ENERGY STAR®compliant
Remote management
Basic management (default)
iDRAC7 with Lifecycle Controller Express (upgrade)
iDRAC7 with Lifecycle Controller Enterprise (upgrade)
8GB vFlash media (upgrade), 16GB vFlash media (upgrade)
Systems management
Dell OpenManage Essentials
Dell Management Console
Dell OpenManage Power Center (requires iDRAC7 Enterprise with Lifecycle
Controller 2.x)
Dell OpenManage Integrations and Connections:
OpenManage Integration Suite for Microsoft®System Center
Dell Management Plug-in for VMware®vCenter™
Connections for HP Operations Manager, IBM Tivoli® Netcool®and CA Network
and Systems Management
IPMI 2.0 compliant
Rack support
ReadyRails™ II sliding rails for toolless mounting in 4-post racks with square or
unthreaded round holes or tooled mounting in 4-post threaded hole racks, with
support for optional toolless cable management arm
ReadyRails static rails for toolless mounting in 4-post racks with square or
unthreaded round holes or tooled mounting in 4-post threaded and 2-post
(Telco) racks
Operating systems
Microsoft Windows Server®2008 R2 SP1, x64 (includes Hyper-V™ v2)
Microsoft Windows®Small Business Server 2011
SUSE®Linux®Enterprise Server
Red Hat®Enterprise Linux®
Optional embedded hypervisors:
Citrix®XenServer™
VMware vSphere™
Red Hat Enterprise Virtualization®
For more information on the specific versions and additions, visit
Dell.com/OSsupport.
1GB means 1 billion bytes and TB equals 1 trillion bytes; actual capacity varies with preloaded material and operating environment and
will be less.

The Dell PowerEdge R420 is a 1U, 2-socket rack server. For additional system views and features,
see the Dell PowerEdge R420 Systems Owner’s Manual on Support.Dell.com/Manuals.
Figure 1 shows the features on the front of the R420 chassis including eight 2.5-inch hard drives,
control panel, USB connectors, and many other components and features described in this guide.
Figure 2 shows the optional lockable bezel on the front of the R420 chassis.
Figure 3 shows the features on the back panel of the R420 including USB connectors, Ethernet
connectors, serial connector, video connector, PCIe slots, power supplies, and many other
components and features described in this guide.
The chassis design of the R420 is optimized for easy access to components and for airflow for
effective and efficient cooling. The R420 supports up to 12 DIMMs, 2 processors, hot-plug
redundant power supplies, and many other components and features described in this guide.

Table 4 lists the features on the R420 chassis. For additional information, see the Dell PowerEdge
R420 Systems Owner’s Manual on Support.Dell.com/Manuals.
Feature
Description
Power button
ACPI-compliant power button with an integrated green power LED
Front bezel
Covers the system’s front-loading hard drives and locks for security
NMI button
Used to troubleshoot software and device driver errors; use only if directed
to do so by qualified support personnel or by the operating system's
documentation
System identification button
Buttons on the back and front of a system to help identify the unit in a data
center environment
Hard drives
Up to eight 2.5-inch drives
USB connectors
Connects USB devices to the server
Information tag
Slide-out label panel for recording system information
Video connector
Connects a monitor to the server

Feature
Description
LCD panel and buttons
Displays system ID, status information, and system error messages; two
navigation buttons to scroll through the menu on the LCD and one select
button
Optical drive
Optional slim DVD or DVD+RW drive
Power supply units
Supplies power to the server
Power supply indicators
Indicates whether server has power
NIC indicators
Indicates network activity and status
PCIe slots
Connects PCIe expansion cards to the server
Ethernet connectors
Connects integrated 10/100/1000 NICs to the server
Serial connector
Connects a serial device to the server
iDRAC7 Enterprise port
Dedicated management port for optional iDRAC Ports card
The R420 control panel is located on the front of the chassis as shown in Figure 5. For more
information about the LCD control panel, see the Dell PowerEdge R420 Systems Owner’s Manual on
Support.Dell.com/Manuals.
A useful feature included with Dell PowerEdge 12th generation servers is the Quick Resource Locator
(QRL)—a model-specific Quick Response (QR) code that is located inside the R420 chassis cover
(see Figure 6). Use your smartphone to access the Dell QRL app to learn more about the server.

This QRL code allows you to:
View step-by-step videos, including overviews of system internals and externals, as well as
detailed, concise, task-oriented videos and installation wizards
Locate reference materials, including searchable owner’s manual content, LCD diagnostics, and
an electrical overview
Look up your service tag so you can quickly gain access to your specific hardware configuration
info and warranty information
Contact Dell directly (by link) to get in touch with technical support and sales teams and provide
feedback to Dell
These codes provide an easy way to retrieve the critical support information you need when you
need it, making you more efficient and effective in managing your hardware.
The latest generation of PowerEdge servers has the features listed in Table 5 to help ensure the
security of your data center.
Security feature
Description
Cover latch
A tooled latch is integrated on the top cover with a coin key lock to secure the
system.
Bezel
An optional metal bezel is mounted to the chassis front to provide the Dell ID. A
lock on the bezel is used to protect un-authorized access to hard drives. System
status is viewable on the LCD screen when the bezel is installed.
TPM
The Trusted Platform Module (TPM) is used to generate/store keys,
protect/authenticate passwords, and create/store digital certificates. It also
supports the Intel Xeon TXT functionality. TPM can also be used to enable the
BitLocker™ hard drive encryption feature in Windows Server 2008. TPM 1.2 is
supported. No TPM version is available for China or Russia.
Power-off security
BIOS has the ability to disable the power button function.
Intrusion alert
An internal switch is used to detect chassis intrusion.
Secure mode
BIOS has the ability to enter a secure boot mode through system setup. This
mode includes the option to lock out the power and NMI switches on the
control panel or set up a system password.

The Dell PowerEdge R420 features the Intel Xeon processor E5-2400 product family, which offers
an ideal combination of performance, power efficiency, and cost. These processors provide high
performance no matter what your constraint is—floor space, power, or budget—and on workloads
that range from the most complicated scientific exploration to crucial web-serving and
infrastructure applications. In addition to providing raw performance gains, improved I/O is also
made possible with Intel Integrated I/O, which can reduce latency by adding more lanes and
doubling bandwidth. This helps to reduce network and storage bottlenecks, unleashing the
processor’s performance capabilities.
The new Intel Xeon processor E5-2400 product family provides the following features:
2-socket processor design with power and dimensions optimized for density
Up to 8 execution cores per processor
Intel Hyper-Threading technology enables up to 16 computational threads
Micro-architecture on 32nm process for greater performance per watt
Support for more memory—4 additional DIMMs (up to 12 DIMM slots) and support for up to
16 GB DIMMs increasing the memory capacity from 128 GB to 192 GB
Integrated memory controller with 3 channels of DDR3 and 46-bit physical addressing facilitate
greater memory capacity
Intel Integrated I/O has support for up to 48 lanes (24 lanes per socket) of PCIe 3.0 links capable
of 8.0 GT/s
Faster connections throughout the system with support for up to DDR3 1600 MT/s memory and
8.0 GT/s QPI
Intel Data Direct I/O (DDIO) allows I/O traffic to skip the main system memory and be directed
straight to the processor cache, which can provide a significant reduction in latency as well as
allowing memory to remain in a low-power state
High bandwidth, low latency, bidirectional ring interconnect allows faster access to up to 20 MB
multi-banked last level cache
Intel Advanced Vector Extensions offer up to double the floating point operations per clock
cycle by doubling the length of registers, which can be useful for addressing very complex
problems or dealing with large-number calculations, which are integral to many technical,
financial, and scientific computing problems
Intel Turbo Boost Technology 2.0, which allows processor cores to run faster than the base
operating frequency if it's operating below power, current, and temperature specification limits,
delivers up to double the boost than the previous generation
Continued improvements to both Intel TXT and AES-NI help to better protect systems and data
For more information on the Intel Xeon processor E5-2400 product family, visit Intel.com.
Table 6 lists the Intel Xeon processors supported by the PowerEdge R420. For the latest information
on supported processors, visit Dell.com/PowerEdge.

Model
Speed
TDP
Cache
Cores/
threads
QPI
Max
memory
speed
Turbo
E5-2470
2.3GHz
95W
20MB
8/16
8.0 GT/s
1600MT/s
Yes
E5-2450L
1.8GHz
70W
20MB
8/16
8.0 GT/s
1600MT/s
Yes
E5-2450
2.1GHz
95W
20MB
8/16
8.0 GT/s
1600MT/s
Yes
E5-2440
2.4GHz
95W
15MB
6/12
7.2 GT/s
1333MT/s
Yes
E5-2430L
2.0GHz
60W
15MB
6/12
7.2 GT/s
1333MT/s
Yes
E5-2430
2.2GHz
95W
15MB
6/12
7.2 GT/s
1333MT/s
Yes
E5-2420
1.9GHz
95W
15MB
6/12
7.2 GT/s
1333MT/s
Yes
E5-2407
2.2GHz
80W
10MB
4/8
6.4 GT/s
1066MT/s
NA
E5-2403
1.8GHz
80W
10MB
4/8
6.4 GT/s
1066MT/s
NA
For information on processor installation and configuration, see the Dell PowerEdge R420 Systems
Owner’s Manual on Support.Dell.com/Manuals.
The Intel C600 chipset is implemented on the PowerEdge R420. For more information, visit
Intel.com.

The large memory footprint of the Dell PowerEdge R420 offers greater capacities, higher
frequencies, and more flexibility. The R420 supports up to 192 GB of memory (12 DIMM slots) and
speeds of up to 1600 MT/s, providing high performance in a variety of applications. The new
reliability, availability, serviceability (RAS) features like memory mirroring and sparing help you
increase your uptime and reduce data loss. RAS aids in the rapid and accurate diagnosis of faults that
require service, increasing your memory reliability.
The R420 supports the memory technologies shown in Table 7.
Feature
UDIMM
RDIMM
Register
No
Yes
Buffer
No
No
Frequencies
800, 1066, or 1333MT/s
800, 1066, 1333, or 1600 MT/s
Ranks supported
1 or 2
1, 2, or 4
Capacity per DIMM
2 or 4GB
2, 4, 8, or 16GB
Maximum DIMMS per channel
2
2
DRAM technology
x8
x4 or x8
Temperature sensor
Yes
Yes
ECC
Yes
Yes
SDDC
Yes (with advanced ECC mode)
Yes
Address parity
Yes
Yes

The R420 supports the DIMMs listed in Table 8. For the latest information on supported memory,
visit Dell.com.
Capacity
(GB)
Speed
(MT/s)
Type
Ranks per
DIMM
Data
width
SDDC support
Voltage
2
1333
RDIMM
1
x8
Advanced ECC
1.35
2
1333
UDIMM
1
x8
Advanced ECC
1.35
2
1600
RDIMM
1
x8
Advanced ECC
1.5
4
1333
RDIMM
2
x8
Advanced ECC
1.35
4
1333
RDIMM
1
x4
All modes
1.35
4
1333
UDIMM
2
x8
Advanced ECC
1.35
4
1600
RDIMM
2
x8
Advanced ECC
1.5
8
1333
RDIMM
2
x4
All modes
1.35
8
1600
RDIMM
2
x4
All modes
1.5
16
1333
RDIMM
2
x4
All modes
1.35
16
1600
RDIMM
2
x4
All modes
1.5
Flexible memory configurations are supported on the R420, ranging from capacities of 2 GB to
192 GB. The system supports up to 6 DIMMs per processor (up to 12 DIMMs in a 2-processor
configuration). The R420 has 3 memory channels per processor, with each channel supporting up
to 2 DIMMs.
The R420 supports a flexible memory configuration according to these basic rules:
Speed: If DIMMs of different speeds are mixed, all channels across all processors operate at the
slowest DIMM’s common frequency.
DIMM type: Only one type of DIMM can be used in a system. UDIMMs and RDIMMs cannot be
mixed.
The following additional memory population guidelines apply to the R420:
Up to two quad-rank (QR), dual-rank (DR), or single-rank (SR) DIMMs may be populated per
channel.
DIMMs must be installed in each channel, starting with the DIMM farthest from the processor.
DIMMs should be installed with largest rank count to smallest. For example, if DR DIMMS are
mixed with SR DIMMs, DR DIMMS should be placed in the lowest DIMM slots, followed by the SR
DIMMs.
For more information on memory configuration, see the Dell PowerEdge R420 Systems Owner’s
Manual on Support.Dell.com/Manuals.

The R420 supports memory speeds of 1600 MT/s, 1333 MT/s, 1066 MT/s, and 800 MT/s depending
on the DIMM types installed and the configuration. All memory on all processors and channels run
at the same speed and voltage. By default, the systems run at the highest speed for the channel with
the lowest DIMM voltage and speed. The operating speed of the memory is also determined by the
maximum speed supported by the processor, the speed settings in the BIOS, and the operating
voltage of the system.
Table 9 lists memory configuration and performance details for the R420 based on the population
of the number and type of DIMMs per memory channel.
DIMM
type
DIMM 0
DIMM 1
Number
of
DIMMs
Speed (MT/s)
800
1066
1333
1600
UDIMM
SR
1
∞
∞
∞
DR
1
∞
∞
∞
SR
SR
2
∞
∞
∞
SR
DR
2
∞
∞
∞
DR
DR
2
∞
∞
∞
RDIMM
SR
1
∞
∞
∞
∞
DR
1
∞
∞
∞
∞
QR
1
∞
∞
SR
SR
2
∞
∞
∞
∞
SR
DR
2
∞
∞
∞
DR
DR
2
∞
∞
∞
∞
QR
SR
2
∞
QR
DR
2
∞
QR
QR
2
∞
Reliability, availability, serviceability (RAS) features help keep the system online and operational
without significant impact to performance, and can decrease data loss and crashing due to errors.
RAS aids in rapid, accurate diagnosis of faults that require service. Table 10 describes the RAS
features supported on the R420.
Feature
Description
Dense configuration
optimized profile
Increased memory reliability can be a result from this selectable platform profile
that adjusts parameters to reduce faults regarding refresh rates, speed,
temperature and voltage

Feature
Description
Memory demand and
patrol scrubbing
Demand scrubbing is the ability to write corrected data back to the memory once
a correctable error is detected on a read transaction.
Patrol scrubbing proactively searches the system memory, repairing correctable
errors.
Recovery from single
DRAM device failure
Recovery from Single DRAM Device Failure (SDDC) provides error checking and
correction that protects against any single memory chip failure as well as multi-bit
errors from any portion of a single memory chip.
Failed DIMM isolation
This feature provides the ability to identify a specific failing DIMM channel pair,
thereby enabling the user to replace only the failed DIMM pair.
Memory mirroring:
intra-socket
Memory mirroring is a method of keeping a duplicate (secondary or mirrored)
copy of the contents of memory as a redundant backup for use if the primary
memory fails. The mirrored copy of the memory is stored in memory of the same
processor socket.
Memory address parity
protection
This feature provides the ability to detect transient errors on the address lines of
the DDR channel.
Memory sparing (rank)
Memory sparing allocates one rank per channel as a spare. If excessive correctable
errors occur in a rank or channel, it is moved to the spare area while the operating
system is running to prevent the error from causing an uncorrectable failure.
Memory thermal
throttling
This feature helps to optimize power/performance and can also be used to
prevent DIMMs from overheating.
For information on memory mirroring and sparing configurations, see the Dell PowerEdge R420
Systems Owner’s Manual on Support.Dell.com/Manuals.

The Dell PowerEdge R420 supports internal and external storage options and controllers, different
drive types, and different chassis configurations for a varied number of drives.
Features such as CacheCade™ provide accelerated performance over previous technologies.
CacheCade uses Dell PERC storage controllers to accelerate performance over hard drives or
traditional solid-state drives.
R420 has three chassis to support up to three different drive-bay options.
4 x 3.5-inch drive option (base config, cabled tray)
4 x 3.5-inch drive option (volume config, hot-plug tray; 2.5-inch hybrid kit available for 2.5-inch
drives)
8 x 2.5-inch drive option (maximum drive support in 1U, hot-plug tray)
The R420 supports up to eight 2.5-inch or four 3.5-inch hard drives or solid-state drives.
Self-encrypting drives (SED) are available. Table 11 lists more information about these drives. For an
up-to-date list of supported hard drives for the R420, see Dell.com/PowerEdge.
Form
factor
Type
Speed
(rpm)
Capacities
Nearline SAS*
N/A
500G, 1TB, 1TB SED
SAS
10K
300GB, 600GB, 900GB, 900GB SED
SAS
15K
146GB, 300GB, 300GB SED
SAS SSD
N/A
200GB, 400GB
SATA SSD
N/A
100GB, 200GB
SATA*
N/A
250GB, 500GB, 1TB
SATA
7.2K
500GB, 1TB, 2TB
Nearline SAS
7.2K
1TB, 2TB, 3TB
SAS
15K
300GB, 600GB
*Applies to the 8-drive bay only.