SMB performance much lower than FTP

David Collier-Brown davecb at
Tue Nov 27 05:16:11 GMT 2001

  I have a colleague seeing a very odd behavior with copies
done from a pc client to either a Samba or a Sun "Cascade"
SMB server. 
  The SMB copies are roughly ten times slower than ftp (!)

Louis Caron writes:
| Their application is write intensive - copying
| several largish (1-2GB ) files up to the file server.

| File copies (to the server) are approx. 7-10 times faster with
| FTP vs. PC Netlink
	[PC Netlink is the Sun/AT&T SMB server. In off-line
	discussion, this same effect was seen with Samba --dave]
| (FTP is 70-80  mbits/sec, PC Netlink is 7-10 m/bits/ sec).

| The customer is running: SunFire server 4800, Solaris 8 latest 
| version & patches, NT4 server, SP6. All servers have 100mbits 
| network card, full-duplex.  The file transfer that was tested
| is from the NT4 server to the SF4800 server.

	[The tests were run from the command-line using
	the copy command, and there were no unusual network
	symptoms: errors and collisions were both minuscule]

| We also tested file transfer from one NT4 server to another 
| NT4 server, and we don't notice any performance problem !!!

	This is puzzling: usually we see network problems
	when the performance is much lower, and we diagnose
	them by seeing that the ftp speed is comparable to
	Samba.  In this case, we've a real difference between
	SMB and FTP...

	Before we set up a testing process, can anyone
	suggest why SMB would be orders of magnitude slower
	than FTP on large transfers?

David Collier-Brown,           | Always do right. This will gratify 
Americas Customer Engineering, | some people and astonish the rest.
SunPS Integration Services.    |                      -- Mark Twain
(905) 415-2849                 | davecb at

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