Comment by vitus | Hacker News Reader

Comment by vitus | Hacker News Reader

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Well, it shouldn't be slower than "Read 1,000,000 bytes sequentially from memory" (741ns) which in turn shouldn't be slower than "Read 1,000,000 bytes sequentially from disk" (359 us).

That said, all those numbers feel a bit off by 1.5-2 orders of magnitude -- that disk read speed translates to about 3 GB/s which is well outside the range of what HDDs can achieve.

https://brenocon.com/dean_perf.html indicates the original set of numbers were more like 10us, 250us, and 30ms.

And it links to https://github.com/colin-scott/interactive_latencies which seems like it extrapolates progress from 14 years ago:

        // NIC bandwidth doubles every 2 years
        // [source: http://ampcamp.berkeley.edu/wp-content/uploads/2012/06/Ion-stoica-amp-camp-21012-warehouse-scale-computing-intro-final.pdf]
        // TODO: should really be a step function
        // 1Gb/s = 125MB/s = 125*10^6 B/s in 2003

which means that in 2026 we'll have seen 11 doublings since gigabit speeds in 2003, so we'll all have > terabit speeds available to us.

> that disk read speed translates to about 3 GB/s which is well outside the range of what HDDs can achieve.

That’s PCIe 3.0 x4 or PCIe 4.0 x2, which a decent commodity M.2 NVMe SSD can use and can possibly saturate, at least for reads.

> which means that in 2026 we'll have seen 11 doublings since gigabit speeds in 2003, so we'll all have > terabit speeds available to us.

We’re not that far off. 100GbE hardware is not especially expensive these days. Little “AI” boxes with 400-800 Gbps of connectivity are a thing.

That being said, all the connections over 100Gbps are currently multi-lane AFAIK, and the heroic efforts and multiplexing needed to exceed 100Gbps at any distance are a bit in excess of the very simple technology that got us to 100Mbps “fast Ethernet”.

> That’s PCIe 3.0 x4 or PCIe 4.0 x2, which a decent commodity M.2 NVMe SSD can use and can possibly saturate, at least for reads.

Given that there's a separate item for sequential disk reads vs SSD reads, I think it's pretty clear that particular item meant hard drives specifically. Agreed that modern SSDs should be able to pull that off.

> That being said, all the connections over 100Gbps are currently multi-lane AFAIK, and the heroic efforts and multiplexing needed to exceed 100Gbps at any distance are a bit in excess of the very simple technology that got us to 100Mbps “fast Ethernet”.

Yeah. Terabit networking is not here yet, and it's certainly not "commodity network"-grade. We can LACP a bunch of 100G optics together, but we're probably 5-10 years out for 800G ethernet to become widely adopted and for 1600G to even be developed.

According to Wikipedia, the Power Mac G4 was the first mass produced computer with gigabit Ethernet - in 2000.

So now in 2025, 12.5 doublings later, we should have a mass produced personal computer available with a 1 gigabit times 2^12.5 = ~5 Tbps NIC.

We're not there yet. Not even close.

You are right, but my comment was about a trivial observation: 1 green square is 10µs so half a green square should be 5µs (not 5ns)

So I guess it's a typo but it makes me doubt the other numbers.

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