Hub 4 speed getting 1gig to router, but ethernet half speed except for one PC

[Coder]

Hi all, I have a strange one here. 

I have been suffering random disconnects for months now, and VM keep saying they've fixed it only for it to keep happening. This most recent time I've complained about the disconnects, I was told that upgrading my 500mb package to the 1gig would solve the issues. They promised, and lied, I've had more discos tonight that I'll be complaining about tomorrow. I'm not too fussed about the speed, I just want reliable internet.

My package was upgraded and I received the new Hub4 today. I installed it, but my main PC was only getting around 500mb. I checked with SamKnows & it says the hub is getting the full 1gig connection but my main PC was getting less than half. I have 3 PC's and after much testing, only one of them is getting >950mb while the other 2 are getting <500mb. Here's why it's strange:

I have 3 PC's running on ethernet. 2 of these are wired directly into the Hub4, the other is in my mancave which has an underground ethernet cable running from the Hub4 down the garden 40 meters or so to another router configured as an access point. My 3rd PC is wired into this access point. It is this PC that is getting 950mb+ while the 2 that are wired direct to the Hub4 are around 500mb.

Now, you might think that there's a problem with the link speeds or the cables connecting these 2 PC's, but I can transfer large files from any PC to another and they all run at full speed, 1gig with transfer rates of >100Mbytes. I thought it may be a software issue so I tried booting into safe mode with networking, and it's still the same. So the Hub4, acting as a router, can transfer files to all PC's at full 1gig speed but it can only deliver 1gig internet speed to one of them. I doubt this is a problem with the Hub4, but I'm honestly stuck for what to try next.

Any help?

[ozsat]

Most likely the pc itself is busy doing other stuff and can not cope with 940M.

Try booting the slow ones into safe mode - and try a speed test then.

[Coder]

Thanks for the response, but I did say above that I've tried booting into safe mode with networking and there's no difference. Also, the PC's can easily handle it, as I also said they have no problem transferring files around the network at 1gig speeds. My main PC is more than capable, it's a Ryzen 9 5900x with dual M2 drives set up in a raid array with transfer speeds up to 6GB. There's no issue with capability so it has to be configuration, but at what point?

[OliDude]

Swap the network cables at the router then test speed to devices ??

[Coder]

Thanks for the response, but I've unplugged the Cat6 cable from my main PC and put it into my laptop which gets >900mb so it's not that. Also, all cables must be ok or the network wouldn't transfer files around at full 1gig speed. I can throw a movie which is 5GB in size around the network, and it will transfer at a solid 100Mbytes per second from / to any computer on the network and it all goes through the Hub4.

[Coder · Accepted solution]

Finally I've found a fix to the problem! I'll post here in case others have the same issue.

The network is transferring at full speed so it seems it was Windows that was restricting just the internet bandwidth. I did a bit of googling on this and found that Windows 10 can reserve up to 80% of your bandwidth for background update use. I disabled this feature, which may have helped in solving the issue but did not fix it immediately. Following on the same threads I found a recommendation to try this; open a CMD prompt in admin mode & input the following:

netsh int tcp set global autotuninglevel=normal

That instantly fixed it and my speed is now >900mb.