{
  "id": 18460,
  "title": "Getting 25 Gbps Thunderbolt Ethernet on My Mac Studio",
  "url": "https://urgent.news/2026/07/31/getting-25-gbps-thunderbolt-ethernet-on-my-mac-studio",
  "topic": "science",
  "section": "Science",
  "published": "2026-07-31T16:15:31.000Z",
  "source": {
    "name": "Hacker News Best",
    "slug": "hacker-news-best",
    "url": "https://www.jeffgeerling.com/blog/2026/getting-25g-ethernet-mac-thunderbolt/"
  },
  "original_language": "en",
  "account": "A Mac Studio user sought to upgrade their workstation to support a faster 25 Gbps Thunderbolt Ethernet connection, as their existing 10 Gigabit Ethernet was not meeting their needs. After researching options, they discovered a cheap 25G Thunderbolt adapter utilizing a server-pulled OCP 2 NIC with a Thunderbolt 3 adapter board. At a price of $160, the adapter seemed like a good deal, and they proceeded to test its performance.\n\nThe user faced two issues while testing the adapter: the iperf3 tool on their NAS was outdated, limiting the bandwidth to 15 Gbps, and the adapter enclosure was overheating. They resolved the first issue by updating iperf3, achieving a speed of 20 Gbps. However, the adapter remained hot, so they decided to improve its cooling.\n\nThe user designed a custom fan duct and printed it using Noctua beige PLA to fit the adapter enclosure. They added a low-profile heatsink and a speed-controlled USB fan, securing everything together with screws from the adapter enclosure. After assembling the cooling system, the NIC temperature dropped to under 36°C after 10 minutes of testing.\n\nDespite the cooler temperature, the adapter's maximum speed remained around 20-25 Gbps due to the Thunderbolt 3 chipset's limitations. Real-world testing revealed that the adapter provided only a marginal improvement over the built-in 10G Ethernet, with file copy speeds of around 1.4 GB/sec read and 1 GB/sec write. The user concluded that the effort and cost involved in upgrading the adapter may not have been justified, especially given the slower performance of their low-power Arm NAS.",
  "summary": "Article URL: https://www.jeffgeerling.com/blog/2026/getting-25g-ethernet-mac-thunderbolt/ Comments URL: https://news.ycombinator.com/item?id=49125034 Points: 225 # Comments: 111",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}