Insanely great PCIe 4.0 bit rate locked in
'Boutique' spec aimed at rarified speedsters
"Experts in the PCIe Electrical Workgroup carefully analyzed a number of target bit rates for the next generation of PCIe architecture, taking into consideration several key factors, including our ability to continue using low-cost materials," said PCI-SIG chairman Al Yanes in a statement. "We have concluded that 16 GT/s is a feasible technical solution that satisfies our member companies' requirements."
When The Reg spoke with PCI-SIG's Serial Communications Workgroup chair Ramin Neshati at this year's Intel Developers Forum, he told us "We think we have line of sight to get to 16 gig on copper – maybe even higher."
"Even higher" didn't happen – although, to be frank, there's little reason that it needed to. AT 8GT/s, PCIe 3.0 is as fast as normal humans will ever need.
Well, "ever" may be quite a long time, but Neshati was of the opinion that first, second, and third-generation PCIe would be "good enough for the broad spectrum of applications for a long, long time" – and when we asked him exactly what a long, long time meant, he told us: "Forever."
PCIe 4.0 – which Neshati called "a boutique-type application for very few topologies" – will, however, be welcomed by those building systems in the rarified world of high-performance computing, and may possibly also find its way into data centers tossing around obscene amounts of bits and bytes.
The PCIe 4.0 spec, which is expected to be released sometime in 2014 or 2015, will be backward-compatible with earlier PCIe architectures. The PCI-SIG also says that it is "technically feasible" that it can be implemented with today's run-of-the-mill, low-cost silicon technologies at "approximately" PCIe 3.0 power levels. ®
The PCI-SIG's announcement contained our favorite statistic of the day – and perhaps the month: "Approximately 24 billion lanes of PCIe have shipped in the marketplace since its introduction." Hmm ... that'd be about 3.4 PCIe lanes for every living human being. Are you using yours wisely?
"Forever" and "Who needs more than 640KB RAM"
Sorry, but is history repeating itself?
Build a NAS with more than half a dozen SATA2/SATA3 disks and it's quite easy to start pushing PCIe v2 quite hard, even to the point where it can become an IO bottleneck (ie. typical 8-port PCIe x8 SAS HBA).
PCIe v3 should last a good while, and PCIe v4 that bit longer, but "forever"? I seriously doubt that. Forever is a long time... whatever bandwidth is available we'll find ways to use it all up, and then some.
the length of "forever"
is a finite number. Maybe he knows something we don't.
Locking my bunker door now.
Gates denies ever saying such a thing, and a quick google turns up no definitive references to when or where he might have said it.
Again, varies, but they have them. Or at least every Centrino since 2006 has them (the wifi cards usually connect via PCIe, and PCIe generally replaced the Northbridge)
Use the force, Luke....
If you follow the link embedded in the article, there's a very useful definition of exactly what it means. Raw bits per second per channel, in essence, with a 25% overhead for encoding.