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Getting 25 Gbps Thunderbolt Ethernet on My Mac Studio

89 pointsby speckxtoday at 4:15 PM59 commentsview on HN

Comments

Neywinytoday at 7:24 PM

I'm using the sonnet at work. Work paid for it. Yes it's more expensive. I have gotten over 25 gbps bidirectional, but not by much. Maybe 27. A big downside is that it only supports 15W upstream power which I didn't think to check, so since that laptop only has 2 usb-c ports for power input, it's a bit limiting.

The upside, though, was that I plugged it in, got my throughput, and never had to worry ever again. Remember that engineering time is mucho $$. So troubleshooting overheating, divising a solution, manufacturing it, etc, that all eats into the savings.

The $400 dock would be cool though. It seems smaller than the sonnet and fixes my charging problem. Weirdly I didn't think I'd care about not including transceivers but they did actually come in handy, so that is a downside. Might try to get one of these if I need another one in the future.

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randusernametoday at 7:46 PM

Can't you just put a real PCIe NIC in an eGPU enclosure with a fan? I bet you can solve this problem for like $150 and two craigslist transactions.

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GeekyBeartoday at 6:43 PM

As mentioned in the blog post's footnote, the bottleneck may just be on the NAS side:

> this real-world speed limitation could also be related to my use of my lower-power Arm NAS (running on Ampere Altra, with 32 fairly-slow CPU cores). I was testing writing to an array of fast enterprise NVMe SSDs, so they shouldn't be the bottleneck here.

He was only getting 1 Gigabyte of throughput out of the built in 10 Gigabit Ethernet connection and moving to the 25 Gigabit connection only made a marginal impact on throughput, after all.

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pzmarzlytoday at 5:17 PM

One of the YouTube comments pointed out the issue is most likely the lack of support for SMB Direct (RDMA) in macOS. Would be nice to repeat the test on a Windows/Linux laptop.

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alsetmusictoday at 5:59 PM

Dang, here I was feeling slick with 10Gb between my MBP and Mac mini and NAS. That’s the thing, it could always be bigger / faster / more. It’s enough for my workflow, but it’s fun to see people push further.

brcmthrowawaytoday at 8:23 PM

How does Jeff Geerling afford so many Mac Studios?

teaearlgraycoldtoday at 5:19 PM

It’s crazy that the Ethernet chips consume more power (presumably - because of the heat) than the processor in the computer. How is driving 25Gb/s such a hot task compared to driving multiple 40Gb/s Thunderbolt ports?

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SlavikCAtoday at 5:43 PM

What are typical use cases for needing 25Gbps?

Author talks about 4k video, but AI tells me that for "4K production mastering (ProRes 422 HQ, 4:2:2, 10-bit)" the rate is under 2Gbps.

I'm not saying it's not needed, - just curious.

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nutjob2today at 5:42 PM

Somewhat off-topic: has anyone implemented USB C based networking?

So for instance you have two or more machines that have USB 4 ports at 20 to 80 Gbps and you plug in the appropriate USB C cables to connect them.

What do you need to make the connections appear as a (point to point) part of a regular TCP/IP network? Seems much cheaper than Ethernet if you already have the ports.

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TacticalCodertoday at 7:38 PM

> I can edit 4K video straight off my NAS over the network,

Nothing against Jeff Geerling and I love his YouTube channel and I'm glad he's one of us HNer but this crop of circular "I make YouTube vids about big tx speeds and big NAS because I make vids hence I need big tx speeds and big NAS so I can speak about big tx speeds and big NAS because I make YouTube vids about big tx speeds and big NAS" videos is a bit tiring IMO.

I'm not into cryptocurrencies but, I don't know, host a full Ethereum node, host a Plex/Jellyfin server serving thousands of movies, host LLMs, etc.

I mean: talk about something else than editing vids because you make vids about vids.

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