Why is FTP faster than robocopy, xcopy, or copy/paste methods?

Greetings to all!

I have a question, and I feel really stupid for asking it because I
feel like I should know this answer. Here goes...

I have two servers, one on the east coast and one on the west coast,
that I was trying to transfer 6+ GB worth of information between. The
source server is Win2k and the destination server is Win2k3.
Initially, I was using robocopy to transfer the information because I
wanted reliability; however, the transfer speed was very sluggish and
it seemed as though robocopy was not utilizing the bandwidth correctly.
I did a little research and found an MCP article suggesting that some
servers do not utilize the full TCP window. I did not modify the
registry as that article suggested, but I did try transferring the
information over FTP and received severely increased speed.

My question is why is it that FTP is faster than robocopy in this case?
Is it because robocopy is attaching a lot of information to the packet
that it's sending out, decreasing the amount of bytes available for the
actual data? Does SMB come into play here?

Thank you in advance for your input and answers,

Kyjan

The FTP Protocol is much more efficient. A simple copy (and I assume
ROBOCOPY) uses CIFS, which has some serialized aspects to the code used to
transfer data. Latency on WAN links severlly impact the performamce. This
is also the reason why opening files located across a WAN also takes a
little while longer. Read this article...

http://www.tacitnetworks.com/docs/tollygroupreport.pdf

FTP is the way to go for speeds sake. You can look into WAN optimizers such
as Packeteer which will help a some. You should also investigate Wide Area
File System Solutions from Tacit Networks which may help you achieve what
you are trying to do with Robocopy.

If it is just a onetime copy, just sit back and wait.

"Kyjan" <HolySaphAngel@gmail.com> wrote in message
news:1140184799.894969.261320@g44g2000cwa.googlegroups.com...
> Greetings to all!
>
> I have a question, and I feel really stupid for asking it because I
> feel like I should know this answer. Here goes...
>
> I have two servers, one on the east coast and one on the west coast,
> that I was trying to transfer 6+ GB worth of information between. The
> source server is Win2k and the destination server is Win2k3.
> Initially, I was using robocopy to transfer the information because I
> wanted reliability; however, the transfer speed was very sluggish and
> it seemed as though robocopy was not utilizing the bandwidth correctly.
> I did a little research and found an MCP article suggesting that some
> servers do not utilize the full TCP window. I did not modify the
> registry as that article suggested, but I did try transferring the
> information over FTP and received severely increased speed.
>
> My question is why is it that FTP is faster than robocopy in this case?
> Is it because robocopy is attaching a lot of information to the packet
> that it's sending out, decreasing the amount of bytes available for the
> actual data? Does SMB come into play here?
>
> Thank you in advance for your input and answers,
>
> Kyjan
>

Well, I'm using FTP over the WAN and it's getting the faster
performance. I completely agree with the LAN latency having an effect;
however, when that effect was that I was only getting 10-15%
utilization out of the transfer, I knew something was wrong.

Kyjan