VMG1312 Vs VMG3925

From AAISP Support Site

Thais page describes the differences between the ZyXEL VMG1312-B10D and the ZyXEL VMG3925-B10B routers.

ZyXEL VMG1312-B10D
ZyXEL VMG3925-B10B

The main differences are:

  • VMG3925 is more expensive
  • VMG3925 has 2.4 and 5G WiFi radio, the VMG1312 has only 2.4G
  • VMG3925 has Gigabit Ethernet ports, the VMG1312 has 100M ports
  • VMG3925 is physically larger, even though they are a similar shape
  • VMG3925 has a dedicated WAN Ethernet port, the VMG1312 has a shared LAN/WAN Ethernet port
  • VMG3925 has a better wall mount

Detailed differences

VMG1312-B10D VMG3925-B10B
Dimensions with stand (mm) 160Wx115Hx60D 185Wx147Hx85D
Wall mountable Suboptimal Yes
PSU Rating 12V 1A 12V 2A
CPU/SoC Broadcom BCM63381 Broadcom BCM63168
Architecture BMIPS4350 BMIPS4350
CPU Cores 2 2
CPU Frequency 600MHz 400MHz
RAM 64MB 128MB
Flash 128MB 128MB
Switch chipset Onboard the BCM63381 SoC BCM53125 (Discrete)
LAN Ethernet 10/100M
(To SoC)
10/100/1000M
(To Switchchip)
WAN Ethernet Virtual port from LAN 4 Dedicated 10/100/1000M port
(To Switchchip)
Wireless Protocols 802.11 b/g/n 802.11 a/b/g/n/ac
2.4GHz Wireless Yes Yes
2.4GHz radio chains 2 2
2.4GHz chipset BCM43227 (Discrete) BCM6362 (On BCM63168 SoC)
5GHz Wireless No Yes
5GHz radio chains N/A 3
5GHz chipset N/A Broadcom BCM43602 (Discrete)
SKY85712-21 RF Front-End
xDSL Chipset Broadcom BCM6303 ADSL/VDSL Broadcom BVM6302 ADSL/VDSL
USB Yes, 2.0 Yes, 2.0

You may note that the VMG3925-B10B has a slower CPU, however it also contains more dedicated hardware for packet processing compared to the VMG1312-B10D which needed the extra CPU clock cycles to deal with processing packets.

The VMG3925-B10B's SoC contains 1 Gigabit PHY, which connects to the Switch chip for the WAN and LAN ports. Radios are connected to the SoC, so packets passing through LAN<>WLAN or WAN<>WLAN would be limited to the bandwidth of the single Gigabit PHY inside.