White Rabbit – sub-nanosecond synchronization for large distributed systems
1–10 of 52 posts
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#2Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#3Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
Yes, it uses phased locked loops and measures phase difference between the master clock and the local clock.
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#4Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
It's totally possible to achieve synchronization better than light transmission time. For the purposes of synchronization, the speed of light delay, and any other delay are indistinguishable, and need not be distinguished.
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#5Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
The gravity well time dilation is about 3.5 nanoseconds per meter per year near the surface of the earth. (time changes rate with altitude in a gravity well)
Sub-nanosecond synchronization is getting into the relativity is measurable realm.
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#6Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
Two-way time transfer measures the round-trip propagation time. As a result, it's not directly relevant to the accuracy.
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#7Haven't dug in on the technicals, but this is coming out of CERN, it looks like - and in that light, the links to "We're hiring" on that page almost feel like a flex...
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#8Haven't looked into this in depth but sub-nanosecond sync for systems up to 10km apart is interesting since 10km is about 33 light microseconds. There is some trickery going on.
The gravity well time dilation is about 3.5 nanoseconds per meter per year near the surface of the earth. (time changes rate with altitude in a gravity well) Sub-nanosecond synchronization is getting into the relativity is measurable realm.
That means you get a free clock cycle every 2-3 hours on top of a mountain compared to sea level!
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#9Not on GitHub?
Re: White Rabbit – sub-nanosecond synchronization for large distributed systems
#10Earlier quoted context omitted.
The gravity well time dilation is about 3.5 nanoseconds per meter per year near the surface of the earth. (time changes rate with altitude in a gravity well) Sub-nanosecond synchronization is getting into the relativity is measurable realm.
That means you get a free clock cycle every 2-3 hours on top of a mountain compared to sea level!
Datacenters in spaaaace!