Slow upload speed

I've seen noticably slower upload throughput speed than download speed running on gigabit ethernet. Observed upload speeds are about 500-600 KB/s (~4Mbps), whereas observed download speeds are 9000 -> 10000 KB/s (~80Mbps). Observed speeds uploading files from commandline FTP are equivalent to download speeds. I've experimented with IO buffer settings in Tools -> Settings -> Transfer panel, but I haven't noticed any change in behavior. Is this is problem with the implementation of upload?

-- Erik

Very interesting what you're saying...

Try to update to the latest dev build that is in my sig and tell me if the problem still exists.

PS. try setting the IO buffer to 2

Using the latest dev build (1.0.977.6), upload speed is an order of magnitude slower than download speed:

Upload:

Opening data connection IP: 170.136.138.208 PORT: 2028.
STOR testfile
150 Opening data connection for testfile.
39718912 bytes sent successfully. (625.61 KB/s) (00:01:02).
226 Transfer complete.

Download:

Opening data connection IP: 170.136.138.208 PORT: 2031.
RETR testfile
150 Opening data connection for testfile (39718912 bytes).
39718912 bytes received successfully. (9697.00 KB/s) (00:00:04).

Command Line Upload:

ftp> put testfile
200 PORT command successful.
150 Opening data connection for testfile.
226 Transfer complete.
39718912 bytes sent in 5.87 seconds (6767577 bytes/s)

Hmm... Setting buffer size to 2 seemed to do the trick. Why would setting a smaller buffer size make such a difference? Also, I'd think that increasing buffer size would speed up large transfers, not slow them down.

Here's example throughput using IO buffer size of 2:

Opening data connection IP: 170.136.138.208 PORT: 2083.
STOR runtime_20030603.tar6
150 Opening data connection for runtime_20030603.tar6.
39718912 bytes sent successfully. (6464.67 KB/s) (00:00:06).

Im seeing similiar problems with smartftp

with dos ftp upload and downloads are in the region of 7-9MB/s




ftp> put deathball17.zip



200 PORT command successful.



150 Opening BINARY mode data connection for deathball17.zip.



226 Transfer complete.



ftp: 101526018 bytes sent in 11.18Seconds 9084.29Kbytes/sec.



ftp> get deathball17.zip



200 PORT command successful.



150 Opening BINARY mode data connection for deathball17.zip (101526018 bytes).



226 Transfer complete.



ftp: 101526018 bytes received in 13.53Seconds 7504.33Kbytes/sec.

with smartftp - default 8K IO Buffer, gobal queue downloads
- uploads are consistently either 400KB/s or 800KB/s.. with no in betweens or higher or lower rates. Even when I open up multiple threads, each thread will upload at either 400KB/s or 800KB/s.
- downloads are consistent with what Im seeing in the DOS ftp session.

Uploading using the session queue or direct do not show this wierd behaviour.
[/code]

Set the "IO Buf Size" in the Global Settings.

-Mat