@johsam 

You would frist need to check your connection link rate on each computer.  Make sure its 1000 Mbps or 1 Gbps.  After that make sure your NICs are set to Full Duplex. Then test the connection rate again.

@Carl

I checked again and my PC is connected at 1.0Gbps and so is my Nvidia Shield, both connected to ETH on different decos on the same floor.  I did change from "Auto Negotioation" to "1.0 Gbps Full Duplex" on my lan-adapter and did a reboot but the file transfer speed still maxes out at 11-12mb/s when transfering a file client to client.

@johsam 

Have you tried different types of files.

For example, a folder with 10,000 small files will be slower then one file that is 4 GB (movie).

Are the two computers on the same Deco or are they wired to different units?

The files i'm transfering are +4gb in size. When i tried connecting my laptop to the same deco as my PC running the FTP i get speeds to 30-40mb/s which is great improvement but still a bit slow it youre going to transfer 4TB of data. 

Not really sure where the problem is. What dataspeeds are people getting when transfering data from one client to another?

Ok. I still haven't solved this so im adding a simple sketch of my network.

If anyone could test doing a file transfer between 2 clients connected on ETH (cat5 cable) to 2 different slave decos and post the results it would be great help. 

I did try and connect my PC to the same DECO as my Nvidia Shield and the data transfer speed hits 500mbit. When connected to different slave decos it drops to 100mbit.

@johsam 

To rule out the possibility of distance between the two Decos as being the culprit have both been moved close to each other (same room) and tested?

@johsam Im having same speeds as you describe with only DECO M4R (v2).

@Tony @Carl  could you please give a look to my very similar scenario, but with a single Deco unit

Layout 1:

PC --(eth/Giga)-- SWITCH --(eth/Giga)-- DECO ---(wifi/867mbps)--- Macbook

When copying a large file, I get 14MB/s 

But, if I connetc the MAcbook to the Deco eth.

Layout 2:

PC --(eth/Giga)-- SWITCH --(eth/Giga)-- DECO ---(eth/Giga)--- Macbook

I get ~50MB/s (using both eth ports on the DECO, no wifi)

So I think something is degrading a lot when converting from ETH to WIFI.

As you can see, in my test Im using only 1 Deco and get those 14MB/s (~112mbps) when in Wifi even though the link speed is 867mbps. 

Hopefully this is some software related issue TP-LINK can fix in a comming firmware upgrade.

The worst case scenario is that this product is somehow limited at hardware level and is not good for a single client trying to get the moset bandwith possible.

Note: I use DECO in AP mode, no QoS

@Dj_Mamana 

Good (for me, not for you ofc) to finally see someone that has the same problem. I have tried everything, swapped cables, moved the Decos around but i end up with the same numbers.

It would be nice if someone in the staff could make a similar network setup and test the data transfer speed and post the resaults here.

@Dj_Mamana 

What was used when doing the transfer? FTP? Samba?

Are you able to do an iperf3 speed test? (free software to measure LAN speeds).

@Tony 

Sure thing. I ran this on my android-phone with my PC as server. Phone on WIFI ofc. PC on eth connected to a DECO. 

** edit. My android tv-box uses SMB. But I'm getting the same speed when using FTP on another PC connected to the same network 

Connecting to host 192.168.68.107, port 5201
[  4] local 192.168.68.121 port 40560 connected to 192.168.68.107 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.01   sec  9.85 MBytes  81.4 Mbits/sec                 
[  4]   1.01-2.01   sec  17.5 MBytes   148 Mbits/sec                 
[  4]   2.01-3.01   sec  15.7 MBytes   132 Mbits/sec                 
[  4]   3.01-4.02   sec  13.6 MBytes   112 Mbits/sec                 
[  4]   4.02-5.01   sec  15.9 MBytes   136 Mbits/sec                 
[  4]   5.01-6.01   sec  17.2 MBytes   143 Mbits/sec                 
[  4]   6.01-7.03   sec  5.94 MBytes  48.9 Mbits/sec                 
[  4]   7.03-8.02   sec  13.5 MBytes   115 Mbits/sec                 
[  4]   8.02-9.00   sec  15.4 MBytes   131 Mbits/sec                 
[  4]   9.00-10.02  sec  15.3 MBytes   127 Mbits/sec                 
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.02  sec   140 MBytes   117 Mbits/sec                  sender
[  4]   0.00-10.02  sec   139 MBytes   117 Mbits/sec                  receiver

iperf Done.

Connecting to host 192.168.68.107, port 5201
[  4] local 192.168.68.121 port 40568 connected to 192.168.68.107 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.01   sec  17.1 MBytes   142 Mbits/sec                 
[  4]   1.01-2.04   sec  13.0 MBytes   105 Mbits/sec                 
[  4]   2.04-3.03   sec  14.8 MBytes   125 Mbits/sec                 
[  4]   3.03-4.01   sec  12.4 MBytes   106 Mbits/sec                 
[  4]   4.01-5.01   sec  11.9 MBytes   100 Mbits/sec                 
[  4]   5.01-6.01   sec  16.2 MBytes   135 Mbits/sec                 
[  4]   6.01-7.00   sec  7.66 MBytes  65.0 Mbits/sec                 
[  4]   7.00-8.00   sec  15.6 MBytes   130 Mbits/sec                 
[  4]   8.00-9.02   sec  12.3 MBytes   102 Mbits/sec                 
[  4]   9.02-10.01  sec  16.2 MBytes   136 Mbits/sec                 
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.01  sec   137 MBytes   115 Mbits/sec                  sender
[  4]   0.00-10.01  sec   135 MBytes   113 Mbits/sec                  receiver

iperf Done.