SMB help

Attempting to improve the transfer speed from my DS220+
My setup includes the Synology DS220+ with both LAN ports connected to the router, running WD Red Pro 8TB drives.
ASUS GT-AX6000 Router one 2.5gbps to WAN (1400mbps internet) and the other 2.5gbps to the PC
Windows 10 desktop with 2.5gbps
The smb.conf has been edited with the following lines:
server multi channel support = yes
aio read size = 0
aio write size = 0
I get a bit over 200MB/s transferring files to the NAS but under 100MB/s when transferring from the NAS back to any other drive.
The Synology resource meter shows both LAN ports being used while transferring both directions.
What would cause a much lower transfer from the NAS?


You should probably eliminate your PC hard drive as the bottleneck by setting up a RAM drive and saving the file to that. Windows should be pulling up to 130MB/s even on a 1gbps Ethernet so what we see here on a 2.5gbps interface is much slower. Interesting that it’s dead flat too.

Crystal Diskmark would be helpful too.

writing a file to cache vs reading a non-cached file maybe?
write speed of your PCs hard drive being too slow?

I would definitely do as wayland suggested and set up a RAMdisk on your PC. Put the file into it and then write that to the NAS. Then delete the file out of your PC’s RAMdisk and try copying the file from the NAS back to your PC. That will eliminate drive speed on your PC as any issue.
I would also attempt the test of copying from NAS to your PC a second time right after the first test, just to see if the NAS changes speed with a cached file or not (depending how much RAM you have in your NAS)