The speed looks fine for me on the Laptop itself:
/dev/sda:
Timing cached reads: 28080 MB in 1.98 seconds = 14161.28 MB/sec
Timing buffered disk reads: 448 MB in 3.02 seconds = 148.55 MB/sec
/dev/sda:
Timing O_DIRECT cached reads: 604 MB in 2.00 seconds = 301.42 MB/sec
Timing O_DIRECT disk reads: 454 MB in 3.02 seconds = 150.36 MB/sec
On the Pi itself i get:
/dev/sda:
Timing cached reads: 1974 MB in 2.00 seconds = 988.54 MB/sec
Timing buffered disk reads: 196 MB in 3.02 seconds = 64.91 MB/sec
/dev/sda:
Timing O_DIRECT cached reads: 122 MB in 2.01 seconds = 60.64 MB/sec
Timing O_DIRECT disk reads: 194 MB in 3.03 seconds = 64.03 MB/sec
This also much above the speed, i got, when i transfer files via SFTP/SCP.
I have tested also iperf and got:
0.0000-10.2100 sec 113 MBytes 93.1 Mbits/sec
It seems like this is really somewhere limiting to 100MBit.
It seems the limiting factor is the switch or cable. If i connect the Rpi to the router directly, i get:
0.0000-10.1222 sec 281 MBytes 233 Mbits/sec