That is cool. I use a gps NTP server on my home network and live with sub-millisecond time sync. I’d go PTP but the equipment is a bit too expensive if the only value add is better time sync and I don’t need additional bandwidth. Prices coming down would be nice.

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Youden 3 hours ago | parent [-]

What's expensive? PTP is widely supported on commodity hardware these days. I think most Intel NICs support it, quite a few Realtek and a lot of embedded stuff, down to even MCUs like STM32.

Even if you want a NIC with a stable oscillator or GPS inputs to act as a grandmaster, you can buy an E810 with the necessary hardware from eBay etc. for a few hundred or DIY something yourself much cheaper.

	▲	geerlingguy 2 hours ago \| parent \| next [-]
		Switches that properly support PTP are expensive, at least for now. You can achieve microsecond accuracy with a lot of non-timing-specific networking hardware, but it's around as good as you get with modern NTP... To get sub-microsecond, you need hardware that supports transparent/boundary clock and doesn't just 'say' it does, but actually does (vendors have stamped PTP support on things that definitely don't account for time correctly internally!).
	▲	jcelerier 2 hours ago \| parent \| prev [-]
		out of dozens of laptops and computers we have where I work, we have maybe 3 that have a PTP-compatible NIC.