Windows network drives limited to 100Mbit/s

[Bikkies]

Is there something specific to SABnzbd that would be causing it to limit write speeds to exactly 100Mb/s for mapped network drives?

I'm using SABnzbd 2.3.9 [03c10dc] on a Windows Server 2019 VM.

I have a 250Mb/s down connection and if I change the incomplete location to a local drive I can get a constant download speed close to 30MB/s, but if I change the incomplete location to a mapped network drive I get a fast speed for a few seconds and then it tanks to below 10MB/s, and tends to hover around 3-5 and I can see constant network traffic capped at 100Mb/s going to the network drive.

I can copy to and from these drives at perfect gigabit speeds using windows file copying and anything else I've tried on the machine, but for some reason SABnzbd specifically seems to be limited.

I even tried to trick it by making a symbolic linked folder on the C drive to a folder on the network share, so that SABnzbd thought it was just writing to C ... that was definitely a long shot and didn't work, the speed was still capped.

If I do the writing speed test in SABnzbd, with the C drive I get ~100MB/s, but the network drive gets around 12MB/s, right on the limit of 100Mb/s.

[sander]

I can copy to and from these drives at perfect gigabit speeds using windows file copying and anything else I've tried on the machine

How did you measure that?

[mrkake]

I'm having a similar issue.

Basically I have sabnzb using the NAS as incomplete and complete folder. I expect this to be slower than using local HD, but it's true that it is MUCH slower.
I can measure it from Task Manager looking at network traffic, which max out between 100-200mbit for me.

But for example, if I copy a large file manually using windows explorer, from the same machine where sabnzb is running, it can easily hit 700-800mbit consistently (in addition to the 100-200mbit from sabnzb that does not slow down or change at all while the file is copying).

So it's clear that somehow the speed bottleneck is sabnzbd itself or something it is doing versus the NAS or network limitations.

[Bikkies]

I can copy to and from these drives at perfect gigabit speeds using windows file copying and anything else I've tried on the machine

How did you measure that?

Mostly via Windows file copy. It reads and writes at 113MB/s. It gives around 960-970 Mbps stable transfer speed looking at task manager.

But now I have also done a test with LAN Speed Test, with it's limit of only testing a single packet for the transfer it's giving me a result of ~310Mb/s write and ~850Mb/s read. But other things that transfer stuff to the drives seem to get up into that 900+ number on the writes according to task manager.

I switched over to NZBGet to see if it has the same issue, and it doesn't. I'm getting very consistent download speeds and I can see it periodically sending a whole bunch of data to my network drives at a good speed.

[safihre]

You should not set incomplete folder ever to a network drive.
NZBGet handles the incomplete files differently than we do, so we need a faster response to reads and writes.