| ▲ | Getting 25 Gbps Thunderbolt Ethernet on My Mac Studio(jeffgeerling.com) |
| 38 points by speckx 2 hours ago | 20 comments |
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| ▲ | alsetmusic 2 minutes ago | parent | next [-] |
| 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. |
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| ▲ | pzmarzly 43 minutes ago | parent | prev | next [-] |
| 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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| ▲ | teaearlgraycold 42 minutes ago | parent | prev | next [-] |
| 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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| ▲ | AnthonBerg 21 minutes ago | parent | next [-] | | As I understand it, it takes a bit of anger to get electromagnetism to wiggle that fast over copper. Imperfect transistors using their full operational envelope to control a sort of chaotic thing? Fields and stuff. | | |
| ▲ | m463 14 minutes ago | parent | next [-] | | can confirm. anger causes loud fast communication that can be heard over background noise. I've heard anger using light-based signalling like sign language might be more efficient. | |
| ▲ | teaearlgraycold 11 minutes ago | parent | prev [-] | | They get hot using fiber as well. |
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| ▲ | wmf 30 minutes ago | parent | prev | next [-] | | A Mac Studio is over 100 W while a 25G NIC is under 25 W (that's the power limit for a normal PCIe slot). | |
| ▲ | throwaway219450 24 minutes ago | parent | prev [-] | | They’re not that bad, but even a couple watts of power with no way to dissipate is going to get hot enough to burn you. Forced air cooling over a heatsink is really effective. 15W under load is much lower than a high end desktop CPU that can pull 150-200W. See also NVMe drives? They draw enough idle power to drain a laptop battery overnight, and will easily hit 60+C in a bad enclosure. That’s only a 10Gbps module. The USB4 enclosures are all heatsink. |
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| ▲ | SlavikCA 17 minutes ago | parent | prev | next [-] |
| 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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| ▲ | nutjob2 18 minutes ago | parent | prev [-] |
| 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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| ▲ | davkan a minute ago | parent | next [-] | | I used to have a thunderbolt ring network for a ceph backend on my k8s cluster. Ethernet over thunderbolt is in the kernel, they show up as Ethernet interfaces and you just directly connect them. Latency was an order of magnitude higher than twisted pair but the throughput was greater than 10Gbps and I didn’t have to spend on 10GbE capable servers and network equipment. I vaguely remember that they had to be Thunderbolt not just USB-C. | |
| ▲ | imoverclocked 14 minutes ago | parent | prev | next [-] | | Yup, totally doable. Of course, it’s a point to point link so if you want to build a whole cluster that way then you’ll need a lot of usb-c ports or you’ll need to make more of a mesh topology. I believe MacOS supports it via the usual network control panel. I’ve used it for transferring data from an older laptop to a newer one. The cable is more expensive than fiber, last time I checked. | | |
| ▲ | QuantumNomad_ 6 minutes ago | parent [-] | | I have also used a USB 4 cable to network two MacBook Pros to one another and can confirm that it was very simple to connect and it was fast as heck. The USB 4 cable I used was rated for up to 40 Gbps. |
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| ▲ | warpflyght 7 minutes ago | parent | prev | next [-] | | Yes, there are a few standard(ish) mechanisms for doing this, like [RNDIS][1] and NCM. If you have two Thunderbolt-equipped Macs and connect their ports together, you can use Bonjour/zeroconf for network discovery between them. [1]: https://en.wikipedia.org/wiki/RNDIS | |
| ▲ | robin_reala 16 minutes ago | parent | prev [-] | | USB-4 is basically Thunderbolt right? Thunderbolt networking is pretty automatic on Macs at least: https://support.apple.com/en-gb/guide/mac-help/mchld53dd2f5/... |
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