I'm having the same issue with version 1.3.94. I have btsync running on three machines, 2 x linux_x64 and 1 x raspberry pi arm. The CPU load on the linux machines seem to be reasonable after peak time. The raspberry pi however has a constantly high load of 70-80%. The sync.log shows these lines, no output for a long time after that (while high CPU load) [20140518 01:14:34.795] Incoming connection from *****:34477[20140518 01:14:35.911] Got id message from peer ***** - ***** (*****) 1.3.94[20140518 01:14:35.912] Got state sync request from peer *****[20140518 01:14:36.169] Merge: processing get_root message, my hash: *****[20140518 01:14:37.858] Merge: processing get_have_pieces message, my hash: *****, prev hash: *****[20140518 01:14:39.235] State sync finished for folder /media/GIGABEAT_2/btsyncMy synced folder resides on a USB connected harddrive and is mounted as: /dev/sdb2 on /media/GIGABEAT_2 type ext4 (rw,nosuid,nodev,uhelper=udisks)Ext4 itself should not be the problem, as my linux machines also sync to ext4 filesystems. The mount flags might be a problem?