Are your FTP uploads slow when using Windows Explorer and Internet Explorer, compared to when you do the same with the command prompt? If so then this article may interest you.

FTP or File Transfer Protocol is a standard network protocol, used to copy a file from one host to another over a TCP/IP-based network, such as the Internet.

KB2388131 explains the reason for this happening as follows! Windows Explorer and Internet Explorer have a default send buffer size of only 4096 bytes. Due to this default size, FTP uploads initiated from Windows Explorer and Internet Explorer will be slower when compared with command prompt.

ftp.exe with command prompt does have a configurable send buffer size.

To specify a custom buffer size in the command prompt, type in:

ftp.exe -x:buffersize in bytes (eg. 8192)

You will then see the following message:

SendSocketBuffer: 8192 Bytes

The send buffer size is now set for this session and you can then proceed with the FTP connection.

These links may also interest you:
How to map an FTP drive / folder in Windows 7 and Vista
Top free FTP Applications for your Windows PC.