GoKawiilHomelab troubleshooting traces 10GbE slowdown to Intel E610 driver's default receive buffers
A homelab operator upgrading to a UniFi UNAS Pro 8, an Intel E610-XT2 10GbE card, and a Minisforum MS-01 miniPC found file transfers crawling at 100-200 Mbps despite all hardware reporting a full 10 gigabit link. After ruling out the NAS, its RAID array, SSD caching, Immich, SMB signing, and Windows Defender, an iperf3 test isolated the problem to networking between the desktop and the MS-01, revealing nearly a million discarded received packets on the Intel adapter. The root cause turned out to be the E610 driver defaulting to 512 receive buffers instead of its supported maximum of 4096.
GoKawiil's interpretation of the reporting above, not reported fact.
The case shows how a seemingly simple 10GbE upgrade can be undermined by conservative default driver settings that silently drop packets rather than failing outright, making the issue hard to diagnose without granular tools like adapter statistics and iperf3. It's a useful reminder for anyone building a homelab or small business network that link speed reported by software doesn't guarantee actual throughput, and that NIC driver tuning is often overlooked during hardware upgrades.
- Reported 10GbE link speed does not guarantee real-world throughput if NIC drivers use conservative default settings.
- Systematic isolation with tools like iperf3 and Get-NetAdapterStatistics helped rule out NAS, RAID, and software causes.
- The Intel E610-XT2 driver's default receive buffer of 512 (versus a supported 4096) caused packet discards and severe slowdowns.
Ubiquiti UniFi UNAS Pro — This is the very NAS at the heart of the article's 10GbE homelab saga inch a rackmount UniFi network storage box with a built-in 10G port and room for a stack of drives. If you're consolidating a home lab onto the UniFi ecosystem, it slots right into the same controller UI as the rest of your gear.
See Ubiquiti UniFi UNAS Pro on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: hanselman.com, 2026-08-28
Published there as: “Debugging my new network, when 10 Gigabit Ethernet Runs at 300 Megabits”
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