0

I have an SSD drive connected to my router's USB 3.0 port. My computer is connected to the routeur directly through ethernet (no switch) and runs Windows 10. When downloading files from the internet my download speed tops around 40 MB/s. However, transfers between my computer and the routeur's drive are much slower:

  • 30 MB/s while copying from the router's drive to my PC
  • 12 MB/s while copying from my PC to the router's drive

I tested with wifi both on and off on the router to account for potential wifi interference with USB and the results were the same. My computer's network adapter should go up to 125 MB/s, theoretically. And I tested the drive's performance while directly connected to my PC via USB 3.0: read and write speeds were both good.

I'm curious to what's slowing down local transfers on the network, particularly from my computer to the shared drive. My first guess was to blame the SMB protocol used to transfer files locally (the router uses SMB1). But I read (for example here) that SMB transfers on similar networks would go up to 80 MB/s.

What else could cause the slow transfers? Why would I get different speeds while tranfering from and to the router's drive?

Router's specifications:

  • dual-core ARM Cortex A9 1 GHz
  • 1 GB RAM + 512 MB flash memory
  • Giga-Ethernet
  • USB 3.0

Note: all the speed values are in megabytes per second.

user236356
  • 1
  • 1

1 Answers1

0

Many wireless routers with USB ports are known to be slow. Take a look at the review of this AC1900 by PC Magazine.

I am surprised that, with all that muscle inside the AC1900, a file-copy job to a USB drive attached to its USB 3.0 port could be so slow. I tested read and write speed using a 1.5GB video, a client connected to one of the router's LAN ports, and a Western Digital My Passport drive attacked to the USB port. Write speed averaged a glacial .83MBps and reads were a similarly dismal 1.28MBps.

There are a couple issues at play. Slower CPU speeds, USB 3.0 interference from wifi, unoptimized hardware or software in the USB stack...

Bert
  • 2,863
  • 12
  • 13
  • I did some more tests with wifi on and off and edited my post. It doesn't look like wifi interference with USB. So the last possibility seems to be the router's usb hardware. – user236356 Jan 05 '21 at 13:07