Slow LAN speed Windows 10

[garyjsalmon]

I have searched for a solution but no luck - I have a windows 10 desktop with a gigabit network card connected to a gigabit switch to a gigabit router to which is connected a gigabit NAS, all with Cat 5e or better cables. I have followed every suggestion I can find but the following problem persists. If I transfer files in Windows Explorer I achieve a steady 11.1MBs. If I pause and restart the transfer the speed jumps to around 135MBs, and then slumps back to 11.1 (or occasionally stops altogether) before completing the transfer.
So, the potential for a fast file transfer exists - it just doesn't achieve it. Ideas please. (Please excuse any imprecision in my description - I'm no.expert!)
Many thanks.

 

[kanewolf]

It shouldn't matter, but start by moving the NAS connection to the same switch as the host. See if that has any impact. It is possible that you have some option (QOS, or something) that is impacting the LAN performance on the router.

 

[TJ Hooker]

If you have slow HDDs, 11 MB/s may be as good as they can do depending on the sort of files you're transferring.

 

[garyjsalmon]

If you have slow HDDs, 11 MB/s may be as good as they can do depending on the sort of files you're transferring.

Thanks for the reply. I had considered this, but am curious why I can temporarily achieve a much higher speed. It could be there is a buffer that initially accepts the faster transfer - but that would suggest that every transfer would start quickly and then slow, when I actually only achieve the high speed after I have paused a transfer. An un-paused transfer just chugs along at a steady 11.1

 

[garyjsalmon]

It shouldn't matter, but start by moving the NAS connection to the same switch as the host. See if that has any impact. It is possible that you have some option (QOS, or something) that is impacting the LAN performance on the router.

Thanks for the reply - I shall try linking the NAS directly to the switch as by rights everything should then communicate at gigabit speed. I have previously connected it in this way [didn't test the speed though!] and the NAS lost visibility on the network so I moved it back - I use it to stream to the TV among other things.

The router doesn't have accessible QoS, or at least I can't find it. The router is a Linksys 3200ACM that has been flashed to run a VPN. The speed is unchanged whether the VPN is running or not, but I do suspect this may be the bottleneck.

UPDATE - Thank you Kanewolf.
I've moved the NAS onto the same switch and now have transfer speeds of up to 130MB/s - so the issue is the router.
I've made the NAS visible on the network and reset shares for the various devices that use it.
Thanks for taking the time to make the suggestion - much appreciated!

 

[kanewolf]

Losing connectivity when connected to the switch is also suspicious. What model is the switch? Most home switches are transparent to all network traffic since they operate at layer 2. You aren't trying to do any link aggregation on the NAS are you ?

 

[TJ Hooker]

If you have slow HDDs, 11 MB/s may be as good as they can do depending on the sort of files you're transferring.

Thanks for the reply. I had considered this, but am curious why I can temporarily achieve a much higher speed. It could be there is a buffer that initially accepts the faster transfer - but that would suggest that every transfer would start quickly and then slow, when I actually only achieve the high speed after I have paused a transfer. An un-paused transfer just chugs along at a steady 11.1

Not if you're being limited by read speed rather than write speed. When you start a transfer, the read HDD would have no way to pre-load the buffer as it didn't know what data would be read until it was requested. When pausing, it's possible the read HDD would load some data into the buffer before stopping and waiting, which results in a short burst of high data rate when unpausing. No idea if that's what's actually happening, but it seems plausible.

But as said above, if you're losing connectivity that points to something else being the issue.