Wrong ETA calculation

[prescott66]

Today i discovered strange ETA calculation, while updating fresh installation of Manjaro.
Update size was 326MB, real download speed was only cca 200kB/s and reamining time(ETA) was 40 seconds and after a while grows up to 2 minutes....so far away from real ETA with that speed.

[philmmanjaro]

ETA is dynamicly based on the given figures from libalpm if I'm not wrong. @guinux, please correct me if needed ...

[guinux]

Download speed is calculated everytime data is received. ETA is calculated from the average download speed so it is not precise in the beginning of the download.

[prescott66]

strange is, that i had constant download speed of 200kB/s and ETA remains 2 minutes during whole download...

[guinux]

It may dues to wrong data from libalpm or a problem in ETA calculation. Let's see there are others reports.

[robert1826]

i also confirm this

[AlpacaRotorvator]

I've been meaning to make precise observations on this for a while now but I always forget and go to sleep while the computer does the updates. What I can say is that even after a few minutes of download pamac still gives an ETA of about 9 minutes, which is a massive underestimation, given that most updates are 700MB+ and I'm sitting on a 1Mbps connection(ie. it actually takes about one hour and a half).

Could it be that whatever algorithm is being used doesn't hold well for cases where the user's bandwidth is much smaller than the total download size?