In general, a single window can also use only one CPU core for the GUI stuff.

Though for me loading 1000 sessions takes about 3 seconds only.
Maybe there's something special about your sessions.
Can you create some configuration with dummy sessions that you can share for testing?

Hi Martin,

definitely it is used in 95% approx, I didn't notice that earlier. Is this the way WinSCP is written or can I change something in order to utilize more cores?

Only a single CPU core is used for the GUI. So check if that is maxed.

Hi,

I've already read all topics related to WinSCP slow startup, but in my case the question is rather different. My configuration consists of more than 1000 sessions categorized in directoies and subdirectories, most of them have also password saved. The problem is that it takes more than 40 seconds before the login dialog appears, but none of the PC resources are fully used, like CPU or disk I/O. Also, when WinSCP is already opened, it needs the same time to open the login screen for a new session.

What WinSCP does when opening New Session dialog? The passwords are already hashed, is it really only about parsing the configuration file?

Martin, can you please send me the newest debug version of the WinSCP so that I can trace the problem?