Hi Hubert,
Thanks for clarification of the definition of Pace1K!
Finally I think that the definition used for pace1k like Geoffrey explained ("Our scenario is show the pace for the first
1km and then keep updating with 100m shift. I am not sure does it meet pace1k definition? ") is okay !
Regarding your explanation: the pack1K will increase accompany with distacne.
One though just slipped out: If first pace for first 1K is 2min,
and then I keep constant pace to run, that means the pace100m is 12sec.
If firmware forgot to clear the pace of previous 100m, the pace1K for 2nd km will be 2min+12sec!
The coming 3nd pace 1K will be 3min+12+12sec!
Since I got flu now, anyboy can help me to check this?
Sincerely,
Geoffrey 
Hi all gps-nerds

!
I tested alittle today, with my Car

, i hold steady around 60 km/h and 40 km/h and started the watch, with avg pace , Pace1k, speed , time , on my custom page.
And i did a few test over around 5 km or so.
And the conclusion is that it is very different results from time to time, so not any given 100 m error or anything like that.
* Example, drove at 60 km/h , avg/pace 1.00 min/km and pace1k started out good but increased to 1.15 min/km , 1.20 , 1.30,stuck there for a kilometer, then 1.27, and thats the time it takes to come 1500m...
* Another time it get stuck at 1.40 for over 3 km , when i hold 60 km/h
Even at 40 km/h it was alot wrong, not following any given pattern.
My guess is that the watch processor (is to weak) cant calculate this correctly, like its get "overheated" with to much work or something.
Will try more, at other more normal walking/running speeds, and try to hold a steady speed, but to find any given error like a calculation error or so will be hard.
Regards
Roger C