Transfer speed is suddenly slow

I have been using a My Cloud Mirror (1st Gen) 6 TB with RAID for 5 years. I use it as a server & not for back-ups. It is on a LAN connected via a 1 Gbps Switch with two iMacs on the LAN both set for 1 Gbps. Link Speed is Auto. It’s DHCP & the WCM firmware is 2.12.127. I connect using SMB 2.

Last week the transfer speed slowed dramatically & using Excel files is no longer instantaneous when updating, saving etc. The same has happened with Lightroom (I keep all files on the MCM). I have not, as far as I know, changed any settings & I have not changed any hardware. The issue is the same with both iMacs & also a MacBook Air (connected through WiFi).

My questions are: should I be looking at the NetGear Switch or the MCM for the problem &, if its the MCM does anyone have any advice as to how to investigate this? I have rebooted the MCM but nothing else.



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