Extremely slow uploads after installing Win7 SP1

[drmca]

Hi,

I've been using FileZilla server since time immemorial and all that time my FTP box did not have SP1 installed on top of Win7 64bit.
For whatever reason I had to install SP1 and ever since then the uploads to my server became painfully slow. I simultaneously upgraded the HDD from 2 TB 5400 RPM to 4 TB 7200 RPM.
My connection is 25/10 Mbit DSL; therefore, the upload goes over the 25 Mbit shoulder and should cap at 2.5-3 MB/s. It used to be that way.
Now whenever I upload files over 100 KB, they start off at about 600 KB/s and immediately slow down to about 160-200 KB/s. Once the file is almost completely uploaded, they stall for 10-20 seconds.
I just upgraded 0.9.57 beta to 0.9.60 beta to no avail.
I thought that I might have inadvertently applied the speed limit to that account, but no, it is set to ignore speed limits. The global seed limit is 200k.

Any idea what is wrong?
If anyone would like to troubleshoot, please let me know and I would create an account for you.

[drmca]

I narrowed it down to FileZilla server by shutting it down and installing Solar winds server instead. It was lightning fast, capping at the interface speed both over the LAN and WAN.
Removed Solar winds, restarted FileZilla and it is painfully slow again.

Is there any interest of the dev team in getting to the bottom of that, or are you perfectly content with the slow transfers?

[boco]

FileZilla Server is currently rewritten from scratch. The current code is unfortunately very dated and not maintainable, anymore. Thus, trying to find and fix issues in it is in vain.

See also viewtopic.php?f=6&t=51579