Share your experiences running OpenVPN client on RT-N66U with Merlin FW

[RMerlin]

today I got RT-AC56U and will be experimenting tonight. I even bought a portable USB fan to cool the router off!

Merlin - could kindly point me in a direction - how to overclock the router?

can I do it using your firmware? what are the commands? thanks in advance!

So the plan is to flash the router with Merlin FW and measure speeds - naked, with VPN and default clocks, VPN with overclocking...

I won't offer any help in overclocking this router because I have no idea if the router will be able to recover in case you set the clock too high (in addition to not having any idea if it would be stable anyway). I don't want to take any responsibility for 150$ bricks, sorry

I'll drop you a hint however: you can manually overclock it the same way as the RT-N66U or RT-AC66U, which should be documented on the web if you try a Google search (or if someone else wants to tell you how).

I only tested it at 1000 MHz and for a few minutes.

 

[Sky1111]

Well, no one asking to OC the router other than me (or my craziness), so I assume responsibility if something goes wrong. and I understand that unlike a PC, there may be no thermal protection, nor there is "clear CMOS" to re-set the BIOS.

I do have questions though:
- how do you monitor temperatures?
- how do you check actual clocks and cores enabled?
- where do you type those commands? I never done that - so is it something I type in the UI or I need to do something more exotic?

thanks!

 

[Sky1111]

figured out the temperature monitoring - Administration - Performance tuning

my little USB fan keeps the router very cool with WiFi power cranked to 200mW /band (with stock, the wireless performance was pretty abysmal) - 43-45 degrees Celsius.

 

[Sky1111]

Holy Smokes!!!

AC56U with stock clocks, running PIA VPN, produced the following results:

Minimum :: 7.04 Mbps | Middle :: 13.78 Mbps | Maximum :: 16.14 Mbps

measured by testmy.net download 200MB random data

Now let's see how fast this beast can go... (as soon as I figure out how to overclock it it)

 

[Sky1111]

Overclocking success!

Radios temperature 2.4 GHz: 43°C - 5 GHz: 45°C

CPU
CPU Model ARMv7 Processor rev 0 (v7l) - (Cores: 2)
CPU Frequency 1200 MHz
CPU Load Average (1, 5, 15 mins) 0.55, 0.13, 0.04

 

[Sky1111]

and now the same 200mb test:

Minimum :: 7.28 Mbps | Middle :: 16.85 Mbps | Maximum :: 23.27 Mbp



that little USB fan from Staples (only $10) does keep the whole thing cool. and surprisingly the fan is pretty quiet.

 

[RMerlin]

Glad it's working out

You will want to monitor the CPU temperature however, not just the radio temps:

cat /proc/dmu/temperature

Those commands can be typed over either SSH, telnet, or from the Run Cmd page.

I'm not sure if that's the real CPU temperature however, that's why I decided not to display it on the webui for now (or else I would get many worried questions about "OMG it looks high, what should I do?" However if you check it at stock and then overclocked rates, it might give you an idea on by how much it actually increases.

And yeah, told you - that router is a beast for OpenVPN

 

[Sky1111]

thanks Merlin - you totally rock!

After running the command, this is what i got:

CPU temperature : 57�C

Question - what does this mean:
CPU Load Average (1, 5, 15 mins) 0.52, 0.24, 0.13

is it 0.52%, or 52%?

 

[RMerlin]

thanks Merlin - you totally rock!

After running the command, this is what i got:

CPU temperature : 57�C

Looking pretty good. I got 72C here @ stock clock.

Question - what does this mean:
CPU Load Average (1, 5, 15 mins) 0.52, 0.24, 0.13

is it 0.52%, or 52%?

It's not a percentage. Linux (and *IX in general) reports CPU load differently from what you might be used.

I think the Wikipedia entry is the best explanation I can get you:

http://en.wikipedia.org/wiki/Load_(computing)

 

[Sky1111]

The router seems to be running very stable and the temperatures are under control... so far so good - external cooling works!

I am thinking to plug the USB fan directly into the USB 2.0 port on the router (not using it anyway) to make the setup less messy. The fan's PSU is rated 5V 500mA, but I have concerns:

- fan motor - can it bring noise to 5V rail in the router and thus impact stability and especially WiFi?
- possible PSU overload - with cranked clocks and WiFi output - I do not know if the power regulators will be OK with full time additional load...

The overclocking devil in me seriously tempts to cut a hole in the rear cover and mount an 80mm ultra silent fan, and power it directly from the PCB with perhaps some RF filters... but I am worried that such proximity of the fan to the internal antennas (any electrical motor generates RF noise!). I had done something like that a long time ago on a Dlink router, but that one had an external antenna...

Any thoughts?

 

[primitivo]

Either I am doing something wrong or RT-AC56U VPN is not as powerful when it comes to VPN as I thought it will be based on RMerlin speed tests

Basically I am using Open VPN setup with Astrill. On my Mac using OpenVPN I am getting 100Mbit, while via router it is only 10Mbit. I don't expect it to be the same, but from what I read RT-AC56U is suppose to have 3x better performance than AC66U which according to users reports VPN speeds were 10Mbit and CPU was bottleneck here. So with RT-AC56U I would expect speeds of close to 30Mbit.

This is not the case though, any ideas why?

 

[Sky1111]

Are you running anything else on the router?
Did you check CPU usage? And of course you using the same VPN server to connect to, right?

I am only on 25mb Internet; before overclocking I was getting like ~13, overclocked speeds are much better. I am planning to make a new post with pictures - cooling is essential when you overclock stuff...

 

[primitivo]

Are you running anything else on the router?
Did you check CPU usage? And of course you using the same VPN server to connect to, right?

I am only on 25mb Internet; before overclocking I was getting like ~13, overclocked speeds are much better. I am planning to make a new post with pictures - cooling is essential when you overclock stuff...

No other devices were using internet via VPN at the time I was checking. However when I launched Apple TV and streamed Netflix + started downloading couple of files on my Mac + doing some speedtest on iPhone, I was able to hit 25Mbps (based on traffic monitor graph).

QoS is disabled on my router, so I don't know why I am unable to hit more than 10Mbps directly on my Mac via router, while I can hit up to 150Mbps with OpenVPN connection directly on my Mac.

I did change Astrill servers (to make sure) and the typical way I measure max speed is to download a good sized file (e.g. 1GB) from leading hosting providers with great connectivity via download accelerator. I am unable to hit more than 1.3 MB/s speed.

CPU load stayed within minimal values though (below 0.08) if sysinfo tab provides accurate results. What kind of CPU load should I expect?

 

[primitivo]

I didn't test it with a VPN provider, but with a tunnel running between my laptop and the router, and iperf running from my laptop to a computer connected on the WAN side, on the other side of the tunnel (the RT-AC56U was sitting inside my LAN for this test, rather than as my main router).

Max WAN to LAN throughput was 240 Mbits (without HW acceleration), and over 700 Mbits (with HW acceleration - bottleneck might have been the Atom used at the other end of the iperf test in that case).

I have checked on my RT-AC56U and during 210 Mbit constant WAN to LAN speed, CPU load was always below 120% without HW acceleration. If it goes up proportionally, it would mean 320-350Mbit speeds should be achievable.

 

[Sky1111]

Don't know what to say.. want to try overclocking?

 

[wizin]

I am so happy, I have preset UK VPN and just turn the client ON, and enjoy netflix UK on all connected devices

 

[primitivo]

Don't know what to say.. want to try overclocking?

Where is your step by step guide with pictures?
My stock clock on RT-AC56U reports 81c temp, I think it is rather high, however I live in a pretty warm and humid climate. Not sure if it is best idea to overlock then.

By the way, my AC56U via OpenVPN produced max results of 16Mbit (I tried TCP port and it was faster than UDP) - same as your results with PIA before overclocking.

My question is why it is a bottleneck if CPU load is below 30%?

 

[primitivo]

VPN speed while running a client on my Mac (15.69 MB/s):

VPN speed via RT-AC56U (2.01 MB/s), CPU Load below 20%:



Any ideas why AC56U is unable to reach higher speeds?

 

[primitivo]

All is clear now, 16 Mbps (2 MB/s) is CPU bottleneck for VPN on RT-AC56U:

CPU0:  1.7% usr  5.5% sys  0.0% nic 79.2% idle  0.0% io  0.0% irq 13.3% sirq

I thought that as it has 2 cores it should be more powerful but this is not the case apparently as OpenVPN is unable to use multiple cores...

 

[Sky1111]

Guys HELP!!!

I went too far by trying to set clocks to 1400 MHz and now I cannot get the router back. Pressed and hold reset button, does not have any effect.
Power cycle - still no love. What is reset procedure using Merlin firmware? Is there restore utility I could try?