10GbE Networking

Beyond gigabit

10 Gigabit Ethernet is 10× the throughput of standard GbE. At ~1.1 GB/s real-world, transferring 100GB between two machines takes under 2 minutes instead of 15+. For a Mac fleet that moves video, datasets, or large repos, the upgrade pays for itself in saved time within months.

What you need

10GbE NICs on each machine. Mac Studio and Mac Pro have built-in 10GbE; Mac mini has it as a BTO option. Other Macs need a Thunderbolt adapter (OWC, Sonnet).
A managed 10GbE switch. MikroTik CRS305-1G-4S+IN (4-port) or CRS310-8G+ (8-port) cover home labs at ~$150–$300.
Cat6a or better cable. Cat6 works at short distances; Cat6a is the safe minimum for full 10GbE up to 100m.

Jumbo frames give you the last 5%

Standard MTU is 1500. Jumbo frames use MTU 9000 — fewer packets per byte transferred, less per-packet overhead, ~5% throughput gain. Every device on the segment must agree (machines, switch, NAS). Mismatched MTU is silent and weird — packets just get fragmented or dropped.

Code

Set MTU 9000 (jumbo frames)·bash

# macOS — set MTU on the Ethernet service
sudo networksetup -setMTU "Ethernet" 9000

# Verify
ifconfig en0 | grep mtu

# Test path MTU end-to-end
# Send a packet of 8972 bytes (9000 - 28 byte ICMP+IP header)
ping -s 8972 -D 192.168.1.11
# If this works, jumbo frames are alive end-to-end
# If you see fragmentation needed errors, MTU mismatch somewhere

Validate with iperf3·bash

# On the server
iperf3 -s

# On the client — multiple parallel streams to saturate
iperf3 -c 192.168.1.11 -P 4
# Expect ~9–9.4 Gbps if everything's tuned
# 1 Gbps = something on the path negotiated down
# In between = MTU mismatch, half-duplex, or CPU bottleneck

Exercise

If you have 10GbE, run iperf3 -c <other-host> -P 4 -t 30. Note the result. Set MTU 9000 on both ends (and the switch). Re-run. The improvement is small (~5%) but real, and verifies your jumbo-frame path is consistent end-to-end. If you don't have 10GbE yet, this lesson is the spec sheet for when you upgrade.