SFP-10G-SR vs LR vs ER: Which 10G Transceiver Do You Need?
Choosing between SFP-10G-SR, SFP-10G-LR, and SFP-10G-ER transceivers? This guide covers wavelength, distance, fiber type, and cost differences to help you pick the right 10G SFP+ module.
The Three Kings of 10G Connectivity
Every data center engineer will eventually face this question: SR, LR, or ER? These three SFP+ transceiver types cover the entire range of 10 Gigabit Ethernet connectivity, and choosing wrong means either wasting money or dropping packets. Here is what you need to know.
Quick Comparison Table
| Specification | SFP-10G-SR | SFP-10G-LR | SFP-10G-ER |
|---|---|---|---|
| Wavelength | 850nm | 1310nm | 1550nm |
| Fiber Type | Multi-mode (OM3/OM4) | Single-mode (OS1/OS2) | Single-mode (OS1/OS2) |
| Max Distance | 300m (OM3) / 400m (OM4) | 10km | 40km |
| Typical Price | $26-$80 | $40-$120 | $80-$250 |
| Use Case | Within building / same floor | Campus / between buildings | Metro / WAN links |
| Power Consumption | Low (~0.8W) | Medium (~1.0W) | Higher (~1.5W) |
SFP-10G-SR: The Workhorse
SR stands for Short Range. Operating at 850nm over multi-mode fiber, this is the most common and cheapest 10G transceiver. Use it for connections under 400 meters, which covers 95 percent of data center internal links. If your switches are in the same building, SR is your default choice.
Key advantages: lowest cost, lowest power consumption, works with inexpensive OM3 and OM4 multi-mode patch cables. The vast majority of top-of-rack to core switch connections use SR modules.
SFP-10G-LR: The Campus Connector
LR stands for Long Range. Operating at 1310nm over single-mode fiber, it reaches up to 10 kilometers. This is the go-to module for connecting buildings across a campus, linking data centers within a city, or any run where multi-mode fiber cannot reach.
Single-mode fiber costs more per meter than multi-mode, but the modules are only slightly more expensive than SR. For new campus builds, many engineers default to single-mode fiber everywhere and use LR modules, even for short runs, to future-proof the infrastructure.
SFP-10G-ER: The Long Hauler
ER stands for Extended Range. At 1550nm over single-mode fiber, it reaches 40 kilometers. This is used for metro links between distant facilities, connecting to colocation sites, or WAN links where leased dark fiber is available.
ER modules cost significantly more and consume more power. Only use them when the distance genuinely requires it. If your link is under 10km, LR is always the better choice.
Compatible vs OEM: Does It Matter?
OEM modules from Cisco, Arista, or Juniper carry the vendor logo and firmware coding. Compatible modules from third parties use the same optics but cost 50 to 80 percent less. For most deployments, compatible modules work identically.
However, some switches refuse to recognize non-OEM modules unless you configure service unsupported-transceiver (Cisco IOS-XE) or similar commands. If you are running a Cisco shop with TAC support contracts, stick with genuine Cisco modules to avoid support complications.
Pro Disk Network carries both OEM and compatible transceivers across all three types. Browse our full selection at prodisknetwork.com or contact sales@prodisknetwork.com for volume pricing.
Decision Flowchart
- Is the link under 400 meters? Use SFP-10G-SR
- Is the link between 400m and 10km? Use SFP-10G-LR
- Is the link between 10km and 40km? Use SFP-10G-ER
- Is the link over 40km? You need DWDM or ZR optics (contact us)
What About 25G and 100G?
If you are building a new data center, consider skipping 10G entirely and going straight to 25G SFP28 for server uplinks. The price gap has narrowed significantly, and 25G modules are backward compatible with 10G ports in many switches. For spine-leaf architectures, 100G QSFP28 is now the standard for inter-switch links.
Pro Disk Network stocks SFP28-25G-SR, SFP28-25G-LR, QSFP-100G-SR4, and hundreds of other transceivers. All modules ship same-day from our US warehouse with free shipping over 150 dollars.