Differences Between OM3 and OM4 Fiber
When deciding between OM3 and OM4, here are a few considerations for you to take into account.
OM - Optical Multimode
Used for short distances, Optical Multimode (OM) is a type of optical fiber with a large core diameter that allows multiple modes of light to propagate inside the core. This allows more data to pass through, however due to the amount of light being reflected and the attenuation that accompanies it, this type of fiber is mainly used for short distances when compared to single mode fiber.
OM3 vs OM4
In terms of OM3 when compared to OM4, all other things being the same (connectors, termination, transceivers, fiber core size (50/125), Laser Optimized Multimode Fiber), the only difference is in the construction of the cable. This difference makes OM4 fiber produce less attenuation, which results in greater signal transmission due to less power loss. The higher modal bandwidth (4700 MHz·km OM4 vs 2000 MHz·km OM3) offered by OM4 allows speeds of 10Gb/s, 40Gb/s, and 100Gb/s over longer lengths when compared to OM3.
Distance Chart OM4 vs OM3
| IEEE Standards | Port Type | Fiber Type | Number of Fibers | Maximum Link Length | |
|---|---|---|---|---|---|
| 10 Gbit Ethernet | 802.3ae | 10GBASE-SR | OM3 | 2 | 300 meters |
| 10 Gbit Ethernet | 802.3ae | 10GBASE-SR | OM4 | 2 | 400 meters |
| 40 Gbit Ethernet | P802.3ba | 40GBASE-SR4 | OM3 | 8 | 100 meters |
| 40 Gbit Ethernet | P802.3ba | 40GBASE-SR4 | OM4 | 8 | 150 meters |
| 100 Gbit Ethernet | P802.3ba | 100GBASE-SR10 | OM3 | 20 | 100 meters |
| 100 Gbit Ethernet | P802.3ba | 100GBASE-SR10 | OM4 | 20 | 150 meters |
Aqua or Violet
To make cable identification easier for OM3 and OM4, the violet color was adopted (first in Europe before proceeding to North America) to designate OM4. This encompasses the cables, connectors, and adapters.
