Slow download on network drives

[Zazou]

Hello,

I have some problems download speed with FileZilla.

• My connection is 500 dl /400 up.
• Windows 10 Pro on both computers
• Gigabit switch
• 2 computers on the network
• FileZilla 3.48 on both computers

No problem when I download a file on my computer from a SFTP connection, I'm at around 60 Mb/s. When I download a file to a connected drive on my network it never exceeds 2-2,5 mb/s.

-If a transfer a file from my PC to the other computer by Windows explorer I'm at 80 Mb/s. So no problem.
-I installed fileZilla on the other computer and tested a download, no problem, I'm at 60 Mb/s.

To summarize :

SFTP > My computer : 60 Mb/s
SFTP > Network Drive through my PC : 2 Mb/s
SFTP > Second computer : 60 Mb/s
Windows explorer from my PC > Network Drive on the second PC > 80 Mb/s

Do you know with transfers are so slow from my PC to a network drive ?

Thank you

[boco]

Please note that when transferring between an (S)FTP server and a network drive, all data has to be transferred two times (once between the (S)FTP server and local memory/buffer, and once between local memory/buffer and the SMB share). Can get very slow, as SMB isn't the fastest protocol. Especially network adaptors without the full duplex setting applied cannot transfer in both directions at the same time.

While you have a Gigabit switch, what speed and duplex setting was actually negotiated for each PC?

[Zazou]

Hello boco,

Thank you for your answer.

My first PC is in Wifi (802.11ax)
My second PC (the "server") is in "Auto-negociated"

I'll switch to 1.0 Gbps Duplex.

P.S : I have 2 recent PC with SSD (Ryzen 2700x/3700x, 16 GB of Ram, etc).

EDIT: nothing change



I tested the speed of my network to be sure there was no problem.

[botg]

While a slow transfer is ongoing, what latency do you get if you ping the other machine?

[Zazou]

Hello hotg, thank you for you reply :

Without a transfer:


While a transfer:


Seems there are no incidence with the ping.

[botg]

My best guess would be lack of a write cache for the network share. With SFTP, the write sizes can be small. Without caching for each of the writes, the software has to wait for the system to send the data over the network to the share and wait for the server to acknowledge it.