DS1512+ Club 3D well configured but not possible to jump over 1GBs

[lolo31660]

Description of the problem

I've successfully configured & plugged Club 3D adaptor on my Synology DS1512+ (cedarview). But using many test I'm not able to go over 1GB/s

Description of your products

• the product name of your NAS model
  • and output of uname -a command
  • DSM version DSM 6.2.3-25426 Update 3
• the product name of the ethernet dongle Club 3D

Description of your environment

• connect directly to a PC or using a hub
  • PC: Asus Xg-c100c
  • Hub: Qnap qws-M1208-8c
• cable category Cat.6

Output of dmesg command

(paste output here)

Output of lsusb command

|__usb8 1d6b:0003:0310 09 3.00 5000MBit/s 0mA 1IF (xhci_hcd 0000:04:00.0) hub
|__8-1 0bda:8156:3000 00 3.20 5000MBit/s 512mA 1IF (Realtek USB 10/100/1G/2.5G LAN 000000001)

Output of ifconfig -a command

eth2 Link encap:Ethernet HWaddr A0:CE:C8:D9:D8:3E
inet addr:192.168.1.13 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: /64 Scope:Global
inet6 addr: 64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:94670288 errors:0 dropped:0 overruns:0 frame:0
TX packets:10343217 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:137666451582 (128.2 GiB) TX bytes:2841984392 (2.6 GiB)

[bb-qq]

Have you tried to enable the jumbo frame?