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throwaway132448 5 hours ago

Tangential question: PCIe is a pretty future-proof technology to learn/invest in, right? As in, it is very unlikely to become obsolete in the next 5-10 years (like USB)?

pjc50 5 hours ago | parent | next [-]

Neither of those is going to be obsolete in 5 years. Might get rebadged and a bunch of extensions, but there's such a huge install base that rapid change is unlikely. Neither Firewire nor Thunderbolt unseated USB.

formerly_proven 4 hours ago | parent [-]

USB4 is the ~third USB protocol stack though (USB1/2 being basically the same iirc, USB3 being a completely separate protocol that neither logically nor physically interacts with USB1/2 at all), heavily based on Thunderbolt to the point of backwards compatibility.

p_l 3 hours ago | parent [-]

USB4 is essentially thunderbolt with some new features and some features being optional instead of mandatory.

formerly_proven an hour ago | parent [-]

A very noticeable feature is that USB4 can tunnel USB3, which means it works like an USB hub, instead of an external PCIe USB controller (like in Thunderbolt). USB2 is still just physically separately transported over the D+/D- pins.

CupricTea an hour ago | parent | prev | next [-]

PCIe is probably the most future proof technology we have right now. Even if it is upheaveled at the hardware level, from the software perspective it just exposes a device's arbitrary registers to some memory mapped location. Software drivers for PCIe devices will continue to work the same.

GrowingSideways 20 minutes ago | parent | prev | next [-]

PCIe expertise will certainly outlive anyone on this forum.

neocron 5 hours ago | parent | prev | next [-]

Might as well be replaced by optical connectors next years, but who knows in advance. Currently there is no competition

pjc50 2 hours ago | parent | next [-]

Hmm. What's the current maths on distance vs edge rate vs transceiver latency vs power consumption on when that would be a benefit? Not to mention how much of a pain it is to have good optical connectors.

I wouldn't expect that to be mainstream until after optical networking becomes more common, and for consumer hardware that's very rare (apart from their modem).

tiernano 5 hours ago | parent | prev [-]

even though it would be optical, it still is using PCIe protocols in the background...

bobmcnamara an hour ago | parent | next [-]

PCIe is still using PCI protocol just over serdes

embedding-shape 4 hours ago | parent | prev [-]

How could you possibly know exactly what protocol they'd be using for the potential future optical PCIe connection? Your guess is as good as anyone's, no?

p_l 3 hours ago | parent [-]

Probably because optical PCI-E is an old thing by now.

In fact, "zero~th generation" of thunderbolt used optical link, too. Also both thunderbolt and DisplayPort reuse a lot of common elements from PCI-E

checker659 5 hours ago | parent | prev [-]

Curious what you mean by learning? Learning about TLPs? Learning about FPGA DMA Engines like XDMA? Learning about PCIe switches / retimers? Learning about `lspci`?

throwaway132448 3 hours ago | parent [-]

Nothing specific! I learned how to implement USB(-C) because there was some specific hardware I wanted to create. I could see the same thing happening with PCIe in future. With USB its longevity was fairly obvious to me, with PCIe I’m not well informed. Thanks for giving me some acronyms to explore!

checker659 2 hours ago | parent [-]

As much as I cringe sharing linkedin articles, this particular series of posts are pretty good: https://www.linkedin.com/pulse/pci-express-primer-1-overview...