The Dell PowerSwitch S4112T-ON is a half-rack-width 1U switch with 12 ports of 1/10GBASE-T copper and three 100GbE QSFP28 uplinks, delivering 840 Gbps of non-blocking switching in a chassis 8.28 inches wide. Two of them mount side by side in a single rack unit.
Where the S4112T-ON sits in a data center
This is the copper half of the S4112 pair, and the case for it is cabling. 10GBASE-T runs over Cat6a on ordinary RJ45 terminations, so a small rack can be wired with patch leads instead of transceivers and fibre. For twelve servers that is a meaningful saving - a 10GbE SFP+ port needs an optic or a DAC at each end, while a 10GBASE-T port needs neither.
It suits small compute islands, branch and edge cabinets, lab racks and out-of-band networks where the servers already have 10GBASE-T LOM ports. The three 100GbE uplinks mean the island still lands on a modern spine at full speed, so choosing copper at the access layer does not date the uplink.
The half-rack width is the second reason. Two units side by side give a redundant pair in 1U rather than 2U - useful in a colocation cabinet billed per rack unit, and in edge sites where the whole footprint is a few Us.
Port layout and breakout math
Twelve 1/10GBASE-T ports handle access. Three QSFP28 cages carry the uplinks and are multi-rate: 100GbE, 40GbE, 2x 50GbE, 4x 25GbE or 4x 10GbE each. Breaking out all three to 4x 10GbE yields twelve more 10GbE ports on top of the twelve fixed, which is the sheet's maximum 10GbE density of 24. Maximum densities are 24x 10GbE, 12x 25GbE, 3x 40GbE, 6x 50GbE and 3x 100GbE.
Port-to-port latency is 2500 nanoseconds against the S4112F-ON's 800. That gap is the 10GBASE-T PHY, not the switching fabric: encoding and decoding a 10 Gigabit signal for twisted pair costs roughly two microseconds and it is inherent to the standard, not a Dell characteristic. For virtualisation, file and general server traffic it is irrelevant. For latency-sensitive HPC or financial workloads, use the fibre model.
Fixed power supplies and fans - and what that means
The S4112-ON is the exception in the S4100 family. Every other model has hot-swappable power supplies and fan modules; on the S4112 both are redundant but fixed, built into the chassis and not field-replaceable. The spec sheet states this directly and then excludes the S4112 from both the replacement-PSU and replacement-fan accessory tables.
Two practical consequences. First, airflow direction is set at manufacture and cannot be changed afterwards - there are no parts to swap. Order the direction that matches your aisle layout. Second, a power supply fault is a chassis fault: the unit keeps running on the surviving supply because the pair is redundant, but restoring redundancy means replacing the switch. For a small site, a cold spare unit is the equivalent of a spare PSU on the larger models.
Operating system and licensing
ONIE is pre-installed and the switch runs Dell EMC Networking OS10 Enterprise Edition, with the same L2/L3 feature set as its larger siblings: OSPF, BGP, policy-based routing, VRF-lite and VLT for multi-chassis redundancy, plus hardware VXLAN gateway support and the full data-center-bridging stack (PFC, ETS, DCBx, iSCSI TLV). As an open-networking platform it will also accept a third-party network operating system. IEEE 1588v2 precision time is supported in hardware only on the 48-port models, not here.
Choosing between the S4000-series models
- S4112F-ON - the fibre twin. Same chassis and fabric, 12x SFP+ instead of copper, and 800 ns latency rather than 2500 ns.
- S4128T-ON - full-width copper, 28x 10GBASE-T and 2x 100GbE, with hot-swappable PSUs and fans.
- S4148T-ON - full-width copper, 48x 10GBASE-T with 2x 40GbE and 4x 100GbE.
- S4048T-ON - the previous-generation 48-port copper ToR with 6x 40GbE uplinks.
Step up when you outgrow twelve access ports or need replaceable power supplies. Stay here when rack width and unit count are the constraint.
Condition, testing and warranty
Refurbished units are cleaned, inspected and functionally tested before they ship: every port is link-tested, both fixed power supplies are verified under load, the fans are checked, and the unit is booted and inspected for fault codes. Configuration is cleared. Units ship with warranty; the coverage tier is selected on this page.
Specifications
| Model | Dell PowerSwitch S4112T-ON |
|---|---|
| Form-Factor | 1RU half-rack width (8.28 in) |
| Ports | 12x 1/10GBASE-T, 3x 100GbE QSFP28 |
| Switching Capacity | 840 Gbps non-blocking, cut-through |
| Forwarding Rate | 630 Mpps |
| Port-to-Port Latency | 2500 ns |
| Maximum 10GbE Port Density | 24 |
| Maximum 25GbE Port Density | 12 |
| Maximum 40GbE Port Density | 3 |
| Maximum 50GbE Port Density | 6 |
| Maximum 100GbE Port Density | 3 |
| Operating System | Dell EMC Networking OS10 Enterprise Edition; ONIE-enabled |
| Layer 3 | OSPF, BGP, PBR, VRF-lite, VLT |
| VXLAN | L2 and L3 gateway supported in hardware |
| Data Center Bridging | PFC (802.1Qbb), ETS (802.1Qaz), DCBx, iSCSI TLV |
| IEEE 1588v2 PTP | Not supported (48-port models only) |
| Layer 2 VLANs | 4K |
| Power Supplies | 2 fixed, redundant, non-removable - AC or DC at build time |
| Maximum Power Consumption | 200W |
| Typical Operating Power | 120W |
| Maximum Thermal Output | 682 BTU/h |
| Cooling | 3 fixed fans (not field-replaceable) |
| Airflow | Fixed at manufacture - I/O to PSU or PSU to I/O |
| Input Voltage | 100-240 VAC 50/60 Hz (DC variant: -40 to -72 VDC) |
| Operating Temperature | 41F to 104F (5C to 40C) |
| Dimensions | 1.7 x 8.28 x 18 in (H x W x D) |
| Weight | 8.45 lbs |
