Thunar progress bar when copying files... BUGGY?

[eccerr0r]

I think this is a bug because Thunar-1.6.10 isn't computing time properly.

I think Thunar is computing time like this:

next chunk:
Get Current Time
Write a chunk
get current time
compute bytes/second
compute time remaining.
goto do next chunk

Reasonable enough, but WRONG. Why?

What if I changed the above to this:

next chunk:
>>> sync;
Get Current Time
Write a chunk
get current time
compute bytes/second
compute time remaining.
goto do next chunk

So basically it seems very optimistic. Right now I'm copying 50GB to a USB2 HDD (20MB/sec) and it's constantly reporting 300MB/sec and 1 minute remaining despite it already taken a half hour, and it just passed half way (32GB copied). It claimed 3 minutes at the get go and kept going down. I manually estimated upwards an hour.

Anyone seeing this behavior? I think the MB/sec progress bar needs to be computed over a longer interval that includes fsync time?
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Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

[duby2291]

Yeah it is buggy. I think there is some kind of caching process going on, maybe the kernel disk cache? Anyway, for the first few moments while cache is filling it -seems- like it is reading the cache speed and then never actually figures out what the actual speed really is. Total guess on my part. But that's what it feels like.