Is the copy speed from ext4 to NTFS the same as from NTFS to NTFS?

Solution 1:

There is no relation between a file server source drive and destination drive (from a format perspective). Unless you have some unusual extra fast network it is not likely to make any difference. The bottleneck on a file transfer over the network is the network transport itself, reading from the server is expected to be faster. Anyway accessing the data from Linux is expected to be faster using ext4 than ntfs.

Solution 2:

Indeed. Systems on both ends of the wire are faster with their own native filesystems. Ubuntu uses a (slower) FUSE driver for NTFS, but ext4 is built into the kernel; NTFS is built into the Windows kernel.