ASUS RT-BE88U: fast wifi, full speed 1gbps ports, VERY slow 2.5gbps ports

[ZoltanTheG]

Hi all,

This is a real puzzler.  Updated entire home network to 2+gbps.  Xfinity gateway/router, 2 RT-BE88U, couple of switches...

Xfinity service is 2gpbs down, 300mbps up.  Depending on specific laptop's capability I get great wifi speeds - from Xfi modem AND ASUS routers.  Some over 1gbps.  Wired direct to gateway I get full download and upload speeds.  Wired direct to either router I get maybe 200-300 mbps down and the full 350 up.  THAT IS connected to any 2.5gbps port.  If I switch to either router's 1gbps port I get 1gbps down and 350 up.  Huh?

Router internal speed test consistently shows 2300mbps down and 350 up.  Something hinky with the 2.5 ports, which FWIW seems to vary a bit depending on the connected client.

Firmware is the latest.  QoS OFF.  Cat5e or Cat6 cables - no difference.

Have an escalated case in with support.  Don't know when I'll hear back.  Cases don't show in my profile.  In the meantime, any suggestions?

Frustrated,

Z.

[jzchen]

Can you find the negotiated connection speed for example Windows Network settings, when connected to the 2.5 Gbps ports.  Because the router speed test seems to get reasonable speed to the Xfinity router right?

[ZoltanTheG]

Thanks for the reply.   IIRC when I checked, Windows said 2.5gbps.  I'll double-check in the morning.

Even if it negotiated incorrectly down to 1gbps, I'd still see higher downloads than I do.  And uploads are full-speed.

Just remembered, when connecting via one of my 2.5 switches, the LEDs indicate 2.5 from router and to client.

Right now I've got my bandwidth-hungry gadgets connected to the 1gbps port just to get some speed.  Of course that negates the $$$ I spend upgrading.

Thanks again,

Z.

[ZoltanTheG]

Windows shows 2.5g connection.  BUT... woke up in the middle of the night w/one more thought...

Had not realized that the Xfi gateway has only one 2.5g port.  The others are 1g - which I had been using for testing direct to modem.

Tried direct to the 2.5g port on the modem - and had the same problem. Slow download, fast upload.

So either the Lenovo-branded 2.5g USB-C dongle, or some setting in both laptops I tested might be the culprit.  Slow on a 2.5 port, fast on a 1g port Think I have ruled out the ASUS routers.

Sorry about the noise, and thanks for replying,

Z.

[jzchen]

Aye,

I didn't catch that you were using those USB to Ethernet converters.  There is an old Intel article on USB noise, that I got into a debate with someone somewhere who said that has been resolved...  Also, ASUS makes one of those USB to Ethernet devices, BUT avoids claim you can use the USB 3.0 to get such high speed throughput.  In fact some router manufacturers have a setting for USB 3.0 compatibility mode, either throttling the USB speed or WiFi speed I forget now...

Well, glad you got to rule out the ASUS router, at least for now...

[ZoltanTheG]

Can't quite tie a ribbon on this yet, but for the interested: test laptop also has both Ubuntu and Fedora Linux installed.  Tested in both using same USB-C dongle and 2.5 router port:  2300 down, 350 up!!!   Getting maybe 200 down and 350 up in Windows.  Something vy sick with how Windows is handling the connection.