@grax 

sorry to disappoint you but it's not better, I've replaced some of those with ER605v2, it's almost 10x faster, about 30MB/s
i have one still in LAB and i have tried everything but VPN is super slow.

  @grax 

VPN varies a lot, the speed goes up and down up and down when I copy a file it varies from 1-10MB/s but mostly around 2-3 MB/s
nice that you brought this up now, I asked TP-Link about this today, this is the answer I got

We have found the root cause of this.

The ER7206 v1 does not support SHA2 acceleration, that is why SHA2 is much slower than SHA1.

We recommend using SHA1 on your ER7206 v1 instead, for better throughput.

Our next version of ER7206, the ER7206 v2 would have great performance in IPSec, up to 600/700Mbps, if you are interested, you may consider upgrading into the v2 version in the near future.

Thanks!

To be honest, it's probably not SHA1 acceleration either, it's almost as slow as SHA2

  @grax 

that's probably all you get, I've tried all possible settings for 2-3 years, it doesn't get much better than that.

did a test now, here is the result. SHA1-AES256-dh2

ER8411 VPN ER7206

  @grax 

it is simply wrong
here is a copy from Between ER8411 and ER605v2

SHA256-AES256-DH14 encryption

  @grax 

You can try :-) 

This is settings I use on ER605v2 

I have`t SHA256 only SHA1 or 2 hmm