Hi,
I was testing network speed on my Raspberry Pi 4 8GB and there was something strange happening (maybe it is just because I use Raspbian but I was curious if someone can confirm/deny it on their Arch install).
iperf3 gives me solid 1Gbps speed
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 1.09 GBytes 939 Mbits/sec 0 sender
[ 5] 0.00-10.00 sec 1.09 GBytes 936 Mbits/sec receiver
But when I copy a big file (1GB and then 4GB) I get only about 40 MB/s. It doesn’t matter if it is on external SSD or directly in /tmp/
(which is mounted as tmpfs
on both devices).
~ >>> scp pi:/tmp/bigfile2 /tmp/
bigfile2 100% 1000MB 40.7MB/s 00:24
the same with rsync
rsync
~ >>> rsync -chavP --stats pi:/tmp/bigfile2 /tmp/
receiving incremental file list
bigfile2
1.05G 100% 40.93MB/s 0:00:24 (xfr#1, to-chk=0/1)
Number of files: 1 (reg: 1)
Number of created files: 1 (reg: 1)
Number of deleted files: 0
Number of regular files transferred: 1
Total file size: 1.05G bytes
Total transferred file size: 1.05G bytes
Literal data: 1.05G bytes
Matched data: 0 bytes
File list size: 67
File list generation time: 6.006 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 43
Total bytes received: 1.05G
sent 43 bytes received 1.05G bytes 34.39M bytes/sec
total size is 1.05G speedup is 1.00
The same gives me ~120 MB/s on my spared laptop on the same ethernet cable.
Could this be something hardware or software related?