Did a couple last night and got fairly similar results unfortunately. (EDIT: Sorry linked to an old one, can't find the new ones logged, prob as I wasn't logged in). Single threaded downstream speed started off at the maximum then dropped to half or one quarter of the potential downstream speed, while multi-threaded was fine.
I've got my Tecsun radio this morning and did a check around the frequencies that were severely affected yesterday evening for a short time but when I'm near the master socket I get very little noise other than from the modem (of course). I'm also thinking of changing my DrayTek for a Ubiquiti EdgeRouter to ensure there's zero doubt that there's a performance problem here that's causing packet loss. Just seems like I'm spending a fair bit of money though in order to eliminate everything my end, I honestly can't believe the DrayTek has an issue.
EDIT 2: I've noticed some noise coming from the UPS which is probably the closest thing to the master socket area so I'll eliminate that by turning it off temporarily. Hopefully I can just switch it over to mains only and it will stop generating noise. One other nearby appliance is my computer equipment, it's under a metal loft bed so maybe the metal frame of the loft bed is acting as an antenna enough for the phone wiring along the outside wall or master socket to pick this up? Only way to be sure would be to turn off the PC but then the stats will stop being monitored too so that's a catch 22. I'll try the UPS first and go from there.
EDIT 3: UPS being off made no difference. Router/modem not going via UPS made no difference. Last possibility I can see is the computer but I doubt it. No update from Zen yet but might be a few more hours.
EDIT 4: Update from Zen tomorrow as the person I'm dealing with isn't in today
. Oh well, these things happen. Otherwise I noticed another significant swing in SNR today, perhaps a little worse than the one yesterday evening.
Edited by Ixel (Mon 04-Sep-17 16:53:38)