No it's not. Normally, WinSCP lists one folder, transfers the files, and then lists another folder, etc. With multiple connections, WinSCP needs a full list upfront. And then it does not list the folders again. So while it takes longer for the first transfer to start, the overall time of the whole operation is the same. Well, actually is shorter, as you are using multiple connections. So turning off multiple connection will definitely make the operation longer.

So, if I turn using multiple connections, it will not do the calculation?

I do not understand "the calculation does not add time to a transfer". I understand it does not slow down downloading but it clearly adds time to the over all process as its spending time calculating instead of going straight into downloading. It appears that about 5 minutes is spent "calculating" when it could just go into downloading. To me, that is time wasted calculating.

Thnx

As documented:
https://winscp.net/eng/docs/ui_transfer_custom#calculate

The option cannot be disabled for background transfers, when using multiple connections. Note that when using multiple connections, the calculation does not add time to a transfer, as directories are not listed again for the transfer itself.

I have downloads set to transfer in the background. I went through each of the transfer setting presets and turned off calculation (unchecked the box). I started the download and it's still "Calculating". This is a huge waste of time as there's a lot of subdirectories. How do I turn this off?

Note: My screen shot shows calculation off for one setting. I confirmed I changed it for all of them.