Hmm......I assume you already updated those network chip drivers? Check for "offload" stuff at device manager for your network chip.

Second, do you use QOS functionality in both routers? If so, disable it.

Set the 'offload' aside first....




I would like to know how you connect first 850l to second 850l.
Yes, I know you mentioned you are using LAN cable, but may I know between which port?
Can you draw a simple diagram of LAN cable and which router port being connected?

I have a suspicion.......

EDIT:

Do you connect via the RED line or BLUE line?

This post has been edited by JohnLai: Sep 1 2018, 03:19 PM

Technically right, at the same time wrong.

Please connect via BLUE line.
Before connecting via BLUE line, MUST disable DHCP (ipv4 and ipv6) on 2nd router.

edit: reason = to avoid WAN to LAN routing/translation on 2nd router, I still don't understand why you still get 350Mbps when you connected your laptop via lan to 1st router though.......
Only ipv4 without NAT acceleration tends to result in 200 - 350Mbps speed. NAT acceleration will be disabled if traffic statistics and QOS being used. But since you said you don't use QOS for both router.......IPv6 doesn't have this issue.
Could it be MTU issue?

This post has been edited by JohnLai: Sep 1 2018, 04:28 PM

Hmm.....maybe you should check if it is caused by spectre and meltdown mitigation as posted by one forummer below?
https://forum.lowyat.net/index.php?showtopic=4649008



Just to be sure, test with CAT 5e cable. Don't TM stock router has extra cable bundled?

Wait lor....pilot phase mah.....or you could contact tm live chat and ask if your unifi account speed is capped correctly.......

Err....didn't you or someone say TM will mass upgrade (more than 5000) everyone from September onward?

No one. However, there are users reporting they got free upgrade to 8Mbps Streamyx.

They didn't get email or website checking either.

They got their free 4Mbps (yes, including your special RM88) to 8Mbps BEFORE and after the turbo announcement.

-.- Maxis is riding on TM fiber backbone.......thus no difference.

RAM cache exist for a reason.
Read and write operation can be coalesced in one off to reduce tear and wear on HDD.

Enable space pre-allocation to avoid serious fragmentation.


~.~ can't get 400Mbps on chrome only eh? Probably CPU bottleneck from chome rendering engine? Oh well....
Remember, don't plug into WAN port for 2nd router, we don't want WAN to LAN routing/translation overhead.....although rt-ac88u cpu can handle it just fine.....

Maybe you should change 'Enjoy our Unifi' to "READ THE 1ST PAGE FOR TURBO RELATED ISSUE"

iphone x = 2x2:2 = 5Ghz 867Mbps LINK speed (433Mbps each), effective PHY layer speed is 400Mbps+

Let just say your receiving device/clients sucks.

The router might be preinstalled with China spyware/surveillance tools too.

Oh? Either both of you are in pilot phase with speed cap.....or you guys turn on 850L QOS function. Remember, if QOS being enabled, NAT acceleration (or whatever the brand name is) will not work.

Try speed test over here
http://www.myspeedmeter.net/
There are ipv4 and ipv6. Try Taiwan server.
Post the result of ipv4 and ipv6 speed test over here.




Err.....first page is missing nat boost, nat acceleration, cut through forwarding, flow accelerator etc and the ipv6 part......

Aside from IPv4 NAT acceleration......

800Mbps users might wanna check if their win10 have an 'older' spectre microcode patch installed.
Remember the one core being maxed in for my old 3570k ivy bridge at 4.2Ghz? I only able to transfer around 650Mbps through the network interface.
Users with low cpu clock might get lesser speed.....~.~

So fast you guys skip to finding NAT acceleration and QOS stuff =.=

Where are the IPv4 and IPv6 results I asked?

Already reboot the hg8240w?

Then can you post your IPv4 and IPv6 speedtest result?
http://www.myspeedmeter.net/
Please select Taiwan server (or other servers)

How many wires in your LAN cable anyway? 8 wires or 4 wires?
If 4 wires = 100Mbps only.

Next, check if the 8 metal contacts from BTU and Router are fine.........(sometimes the metal contact position......off slightly)

.......are both i3 and i5 using windows 10 with up to date patches?