Hi @HJD,
Upload behavior is one of the key things we are currently focusing on in Engineering.
I would be interested to know is if the slowness you are observing is because concurrency is reduced after odrive “settles”. This is the behavior I would expect, especially from Amazon Drive. Amazon’s single file upload speed is fairly slow, comparatively, but each concurrent stream (to a point) multiplies to total transfer speed. Other services have faster single-stream upload, so the drop in concurrency isn’t noticed as much as it is for Amazon because the overall speed is not as affected.
Interestingly enough, the larger concurrency you tend to see on an odrive restart is actually unintended behavior. On init, the current odrive client has a high chance not falling under the intended concurrency parameters. On fast connections this can result is a very high amount of concurrency and faster overall speed on Amazon Drive. Once files start completing, the concurrency drops to the intended levels, which may seem too conservative (i.e. slow) for very fast connections like yours.
In our next major release this whole piece will be overhauled and it will allow better control and consistency.