When Microsoft began the Windows Insider Program last year it was set up with two distribution rings.
The Fast Ring was intended for those users who would be willing to tolerate bugs and system limitations and other issues in order to have the latest builds of Windows 10.
According to Gabe Aul last November only about 10% of Insiders were using the Fast Ring.
That leaves 90% of Insiders who selected the Slow Ring. That ring is intended to be a more reliable and less buggy version of the OS but that meant fewer builds over the course of the Windows 10 Insider Program. The Slow Ring build also serves as the initial build that any new members of the Insider program would receive when getting started and either clean installing Windows 10 or upgrading a current Windows 7 or 8.1 system to the Insider Preview.
Last week, when Fast Ring Insiders received three new builds of Windows 10 in four days, it was believed that one of those builds - 10162 - was a good Slow Ring candidate. In fact, the Windows team had such confidence in that build being right for the Slow Ring that ISOs of it were released late last Thursday before the long three day weekend here in the US.
Then yesterday, as expected, that build was staged to Windows Update so that Windows Insiders on the Slow Ring would see it on their systems and be able to move up to the latest stable build.
We have been told by Microsoft that Windows Insiders will be the first to get Windows 10 on 29 July when it becomes generally available. That means whether you have been on the Fast Ring or Slow Ring for testing purposes over the last several months all Windows 10 Insiders will be prompted to update to the RTM build of Windows 10 on that date.
I am sure the percentages of Insiders on either the Fast or Slow Ring has shifted slightly as the pool of testers has grown to over 5 million people but the majority are likely still opted into the Slow Ring. That means a lot more systems will be hitting Windows Update on 29 July to grab those final bits which will make for a very busy day indeed - much busier than Fast Ring Insiders have experienced in the past.
Imagine the downloading traffic jam if the final bits were made available to everyone at the same time and not just Insiders?