download speed very slow, compared to qBittorrent? HELP!

[Kent]

I download the same seed use qBittorrent and bitcomet, at the same time, qBittorrent is much faster than bitcomet, at least 10x faster.

same computer, bitcomet running on a windows 10 VM, and qBittorrent running on a Ubuntu 16.04 VM, running at same time, 

qBittorrent at 4.6MiB /s

bitcomet at 41KiB /s

is there any config can speed up it?

I have to use bit comet, because the seed is made by bitcomet, after download with qbittorrent, the end of file is missing. it said: 

"_____padding_file_100_如果您看到此文件，请升级到BitComet(比特彗星)0.85或以上版本____"

or, is there a way to download the padding files? I tried to download these padding files, but, I can't find them at the target folder.

 

thanks.

[Kent]

the port forwarding, and fire wall is OK.

at the right corner of bitcomet window, the 2 lights are green.

version is 64bit, 1.73

[Rhubarb]

The 'padding files' are created by BC when a torrent is created from a folder (multiple files). While other apps may not use them, they can quite often 'overlap' torrents (there the beginning or end of a file is actually contained in the bits of the preceding or subsequent file.

Asfor the difference in operation, there are several things to consider - first of all, Gnu/Linux is NOT Windows - it's totally different, Windows can be slower but that's all down to how its network is set up, port forwarding and so on. Download speed can also vary depending on the number of seeds and how fast they are transmitting data. Anotherfactor is in the advanced options - where there are settings for the maximum number of connections and the maximum packet size. There is also a caveat on the 'connection' tab advising you about the relationship between upload and download speeds