On 1/15/21 2:58 AM, Michael wrote: > On Friday, 15 January 2021 08:42:16 GMT bobwxc wrote: >> 在 2021/1/15 下午4:27, Raffaele BELARDI 写道: >>>> -----Original Message----- >>>> From: bobwxc <bob...@88.com> >>>> Sent: Friday, January 15, 2021 08:57 >>>> To: gentoo-user@lists.gentoo.org >>>> Subject: Re: [gentoo-user] network transfer speed >>>> >>>> 在 2021/1/15 下午2:56, the...@sys-concept.com 写道: >>>>> On both of my systems the network card speed is showing 1000 >>>>> cat /sys/class/net/enp4s0/speed 1000 >>>>> >>>>> but when I do rsync larage file I only see about: 20 to 22MB/s On my >>>>> home network I get about 110MB/s between PC's >>>>> >>>>> Both PC's have SSD and the swith is Gigabit (I think). >>>>> How to find a the bottleneck? >>>> >>>> 1000Mbps network card's maximum theoretical speed is about 125MiB/s. >>>> It only works in short distances. >>> >>> Correct but that's the line speed that you'll never reach, when you take >>> into account Ethernet frame overhead, IP (and possibly TCP) header >>> overhead and application ( rsync, FTP, SMB, NFS) overhead you get lower >>> figures. In my experience 900Mbps (110MiBps) on a 1000Mbps line is more >>> realistic for 'normal' transfers. >> Yes, you are right. So it is just *theoretical* speed :-) >> >> I don't know where does the file he sync from. >> If you sync a file from a server in other city, for a 20 to 22MB/s speed >> is very normal. But if in home, that is not good. >> >> And for ftp and rsync. >> ftp is better for transferring a single large file once. >> rsync is better for a long-term, incremental synchronization. The >> file verification of rsync may take a lot of time for first sync. > > There is a theoretical network speed as already mentioned. There is a > protocol speed, which may limit throughput if it has e.g. heavy encryption/ > compression and the CPU is anaemic. Finally, there is a MoBo bus (SCSI/SATA/ > USB) and the media storage limit. If using USB 1.1 or 2.0 and/or the disks > are slow or experience write amplification, you'll find this will constrain > the final transfer speed significantly.
The computers on this network are 2-meters apart and they both use SSD Drive (so USB limitation doesn't come under consideration). Like I said, on my home network when I transfer the 24GB file I get about 110MiBps transfer, so I was expecting the same in remote location). Some units are connected to a router Ausus RT-AC66U B1 but these ports are gigabit too.
