I wanted to build an awesome place for people to discuss module specific issues, but I don't have any more time for this, and there are much better places to discuss Perl-related issues. I'd recommend asking your question on Stack Overflow or on Perl Monks.
If you are looking for a Perl tutorial or Perl-related news, I hope these links will serve you well.
Net-SFTP
Posted on 2010-02-25 08:34:00.481669-08 by rwong
Slow File Transfer
Transfering a 10 MB file takes 40 seconds with the following envrionment: NETWORK: 100 Mbps OS: Redhat ES 3.8 PERL: 5.8.0 If COPY_SIZE in SFTP.pm is changed from 8K to 24K, the performance improved to 28 Seconds. However, this is still slow comparing with Net::FTP (2 sec) or sftp (2 sec) from the command line. Serveral questions: 1)24K seems to be maximum size 2)The COPY_SIZE is used to read the file but the the buufer returning is still 4K 3)Is encrption has anything to do with it?
Direct Responses: 12468 | Write a response
Posted on 2010-02-25 08:51:01.472026-08 by salva in response to 12467
Re: Slow File Transfer
Have you installed Math::GMP? this module is required in order to get Net::SSH::Perl working properly.

Besides that, the implementations of get and put in Net::SFTP are suboptimal and perform very badly in networks with high (relative) latency.

Move to using Net::SFTP::Foreign in order to get transfer speeds similar to those you get using FTP or the native sftp client

Direct Responses: 12481 | Write a response
Posted on 2010-02-26 10:09:43.668833-08 by rwong in response to 12468
Re: Slow File Transfer
The Math::GMP does not make any difference. I also have bignum, Math-BigInt-GMP, and Math-BigRat included from the earlier slow login post. Will try SFTP::Foreign.
Direct Responses: 12485 | Write a response
Posted on 2010-02-26 13:41:15.919871-08 by rwong in response to 12481
Re: Slow File Transfer
Using Net::SFTP::Foreign is comparable to sftp now. Some problems: Running 5.8.0 requires IO::pty and Expect. In Foreign.pm, the version check is disbaled so it does not need Encode.
Direct Responses: Write a response