Coming Soon to Synology: Accelerate Transfers to NAS with Two Cables

Synology comes fromannounce a beta version for its NAS which brings support for an interesting function if you rant against Ethernet speeds: the SMB Multichannel. It allows you to double the performance by using two network interfaces in parallel and macOS has supported it since Big Sur in version 11.3.

Redundancy and performance, but not aggregation

The operation of the technology is a little special: you will not need a switch capable of link aggregation, but simply two network connections, each with an IP address. Apple explains that there are two specific cases, with different behavior.

In the first, you have a wired connection and a Wi-Fi connection. When this is the case, macOS will use the fastest link in theory (probably the cable) and consider the second link as a path rescue. If you unplug the cable, a transfer should therefore continue to work without errors.

In the second case, if the two interfaces offer the same speeds, it is possible to double the speeds. Of course, you will need a Mac equipped with two Ethernet sockets (a Mac Pro, therefore) or two external interfaces, for example in Thunderbolt. the SMB Multichannel can then double the speeds, which promises speeds of around 240 MB/s.

On the NAS side

Pending a possible generalization in DSM 7.2 (the name of Synology’s OS), Kashmir tells us how to proceed. You need a NAS based on x86 processor under DSM 7.1.1 and go activate the beta versions (in Package Center then in Settingsyou have to go tick Yes, I want to see beta versions). The package in question is version 4.15.9 of the SMB Service and you must then activate the SMB Multichannel in advanced settings.

A NAS with two sockets is obviously necessary.

Of course, you will need a NAS equipped with two Ethernet sockets, which is quite common with Synology. To achieve good performance, you’ll also need fairly fast drives, but all modern 3.5-inch drives easily exceed the 120 MB/s allowed over 1 Gb/s Ethernet.