# Slow NFS/SMB/AFP, but fast SCP read performance



## solence (Oct 30, 2018)

Hi!

My FreeBSD 11.2 box has the strange behavior that copying a file via NFS, SMB, or AFP is always capped at exactly 60 MByte/s. However, copying the same file to the same client via SCP immediately hits GBit line speed at 110 MByte/s.

It shouldn't be a hardware limitation, I can read the file with more than 200 MByte/s from disk and the CPU is mostly idle. The data is on a single disk with ZFS on a GELI encryption layer. AESNI support is enabled. ZFS also has 8 GB ARC available.

I have tried to disable atime or sync on ZFS, also setting TCP_NODELAY and larger snd/rcv buffers, but none of it made any difference.

Has anyone any idea what might be wrong?


----------



## JPK (Dec 16, 2018)

Hi,

I am seeing strange behavior as well. However different. SCP sticks below 30MB/sec despite having enough CPU horsepower on both ends. And SMB/AFP shows bursty behavior. Sometimes a few hundred MB go through like a charm and then things simply stall for seconds. No clue what this could be so far.

Did you sort out your issue?


----------



## solence (Dec 17, 2018)

Yes, I found the issue. It's macOS on the iMac I was testing my FreeBSD box with. As soon as I boot the iMac into Windows, the gigabit link is saturated immediately. I wasn't able to find any settings combination on macOS that allows more than 60 mb/s. Windows does 110 mb/s out of the box. Identical setup.

Apple really screwed up here.


----------

