Advice on slow speeds - network diagram attached

Synology
1

I’ve done a ton of testing. I’ve switched out all my network cables to new CAT6e. I’ve rerouted to eliminate intermediate switches. I’ve used multiple PC’s and a Mac to run Blackmagic Disk Speed Test.

I’ve followed the SpaceRex video https://www.youtube.com/watch?v=GmY6KyP9rDE
to optimize settings on both Synology devices (418 and 1522+). I’ve watched most of the other videos too. Thanks Rex!

My 418 with it’s 1Gb/s NIC is maxing out at a pulsing 33MB/s write and 17MB/s read.
My 1522+ with it’s 10Gb upgrade is maxing out at a pulsing 40MB/s write and 64MB/s read.

I do have 2.5 Gb switches and NICs at endpoints so I am not expecting 10Gb speed anywhere. There’s a 1Gb NIC on the 418. I understand the slowest link in the network routes but with these limitations, I think I should get more solid, less pulsing, and higher sustained throughput.

I’m tapped out. At an impasse. Don’t know where to turn. Why are my speeds so much lower than they should be?

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Network
Network1376×1052 324 KB

2

I suggest removing components like the Real HD switch or the TP-Link switch or, ultimately, creating a direct connection between the computer and NAS. This is all for testing, of course.

3

Thanks for the suggestions. I have tried removing the Real HD 5 port switch to no effect or change. I haven’t done a direct connect with no intermediate switch since I ultimately need to run this workflow through a switch with SMB.

4

Test all cables. There are many bad ones in the marketplaces.

5

I had assigned DNS manually to 75.75.75.75 on one and 100.100.100.100 on the other. Once I switched it to automatically assign DNS my speeds immediately went to the max of the network devices.

This is solved.

What’s not solved is why Tailscale kills the speed. I’ll make a new topic.