Why curl ftp upload is so slowly?

[ebogus]

Hello, why when I tried to upload to any host via ftp, upload speed is very slow, but when I use filezilla it's good
I use following code to upload via ftp
C:\123456\soft\curl\curl.exe --ftp-pasv (or without it) --upload-file "filename" -u login:pass ftp://ftp.site.net

Please help me