This post solved my problem. Try manually setting the maximum transmission unit under your system settings>Networks>WLAN/Ethernet>Advanced>Hardware>Custom MTU of 1320.
My Problem was also a mounting delay problem. Once I got things mounted, everything worked normally. Apparently, the default MTU is too high. Manually lowering this made mounting smb shares a much faster process.
The original post I will paste here for the sake of keeping stackexchange self-contained:
I have embarked on a testing mission... Using Wireshark I managed to
see that packets were being dropped when transferring over the network
- the same patterns didn't exist with the same transfer over wireless or the same transfer wired to a Windows server.
So I Googled a little and came up with the following command:
ping -c 1 -D -s 1500 smbserver
It basically pings the server with an MTU of 1500, to which I got:
ping: sendto: Message too long
Note that I also get this error on a Windows server - but what may be
the issue is that when your software gets this response it is supposed
to automatically decrease the MTU until it finds the optimal one for
transfer of packets - something that Mavericks appears to be doing
with Windows servers but not with Linux ones.
So using the ping command I can find an optimal MTU for transfer:
ping -c 1 -D -s 1320 smbserver
Now I get the answer:
round-trip min/avg/max/stddev = 0.829/0.829/0.829/0.000 ms
I had to mess around trying to find the optimal level but it gives you
an idea on the test. After this I take my number and go to:
System Preferences -> Network -> USB Ethernet -> Advanced... ->
Hardware -> Configure: Manually -> MTU Custom: 1320
After this, I disconnected my shares, re-established them and then
tried another transfer up to my Linux server. Success! Granted it's
not what I'd deem to be full speed, but to get a 5GB transfer down
from 8 hours to 30 minutes seems better. It has taken it from
completely unusable to tolerable.
I'm not entirely sure what the root of the problem is as I'm not a
networking expert, as the stepping back of MTU appears to work on a
Windows server and not a Linux one, and it worked fine in previous
versions of OS X, my guess is that it is driver and/or stack related.
BTW I tried updating to 10.9.1 via the Developer download before
trying this, the 10.9.1 upgrade didn't fix the issue for me before I