I first noticed performance issues on my Mac 10.9 (Mavericks) when accessing a Samba4 (smbd/nmbd/samba) server on linux. After investigating this issue, I found that the most important thing to do was increase the size of the buffers on the server.
Initial performance via GigE:
# dd if=/dev/zero of=net/zero.bin bs=10M count=5 52428800 bytes (52 MB) copied, 3.88251 s, 13.5 MB/s
I added the following to smb.conf in the global section:
# Socket buffers should be huge: socket options = IPTOS_LOWDELAY TCP_NODELAY SO_RCVBUF=65536 SO_SNDBUF=65536 # Use sendfile for reading files efficiently: use sendfile = yes # Cache data before flushing to disk: write cache size = 2097152 min receivefile size = 16384 getwd cache = true
# dd if=/dev/zero of=net/zero.bin bs=10M count=5 52428800 bytes (52 MB) copied, 0.473838 s, 111 MB/s
Completely saturate the GigE link (maximum theoretical throughput ~125 MB/s).