Overclocking RT-AC56U

[Sky1111]

Update from my RMA: got my AC56U back to day (this is the second time ASUS tried to fix it). The one I got today works much better than first RMA return, and I got Merlin .40 on it and finally got 1200/800 with BogoMIPS at 2400

Of course the devil inside did not let me stop there and I tried 1400/800. No love, router hung BUT I was able to clear NVRAM by booting with WPS button pressed. At the end, I settled down to 1200/800 and I am happy

Thank you ASUS and thank you Merlin

 

[djdubd]

I have tried overclocking my router and am having trouble getting the clock frequencies to survive a reboot.

I tried using the instructions provided while I was using AsusWRT-Merlin and wasn't able to get them to stick.

I am now using Tomato-Shibby and am having the same issue when I connect via SSH and issue the commands.

I have a recently purchased RT-AC56U, and was wondering if there has been something done to prevent overclocking?

I have already purchased an aftermarket fan and some ABS plastic to mount it to and was hoping to get some extra performance out of my router as I'm not able to max out my VPN connection with the stock speeds.

 

[Adamm]

I have tried overclocking my router and am having trouble getting the clock frequencies to survive a reboot.

I tried using the instructions provided while I was using AsusWRT-Merlin and wasn't able to get them to stick.

I am now using Tomato-Shibby and am having the same issue when I connect via SSH and issue the commands.

I have a recently purchased RT-AC56U, and was wondering if there has been something done to prevent overclocking?

I have already purchased an aftermarket fan and some ABS plastic to mount it to and was hoping to get some extra performance out of my router as I'm not able to max out my VPN connection with the stock speeds.

nvram set clkfreq=1000,800
nvram commit
reboot

 

[3dguru]

Seems like RT-AC68U and RT-AC56U has the same CPU, http://en.wikipedia.org/wiki/Asus_routers

Why don't 56U owners get the DDR 667 upgrade? Any specific reason for that?

Thanks

 

[RMerlin]

Seems like RT-AC68U and RT-AC56U has the same CPU, http://en.wikipedia.org/wiki/Asus_routers

Why don't 56U owners get the DDR 667 upgrade? Any specific reason for that?

Same controller does not imply same memory chip and same board design. The CPU is but one element of the equation.

 

[kamaaina]

Looks like I bricked my AC56U before I could do much. Something must have gone wrong during the regular firmware upgrade. I will try the customer chat and RMA it. It's not responding to any recovery method and I don't plan on doing serial cable stuff. Leaving it offline for now for 30 min, see if that helps.

That said, I have an additional AC68U here as well and was reading the whole thread here post by post. My 68U already shows 83C for the CPU on Merlin .39, the radios are at about 53C, but the CPU is rather high with 83 degrees. All stock settings otherwise, very strange. Only one N network on 2.4 Ghz, 5Ghz off, openVPN client turned off, load at 0.00, 0.01, 0.05 (basically idle), now saying CPU 85 degrees C. I am in room at 21 degrees C, decent ventilation, no extra cooling. This does not look like the AC68U has good heat sinks I guess, no wonder they clocked it down???

I will try OC it to 1000 for a few minutes later this week and see how that might affect the temp. At 83 degrees I guess I won't keep it OC'ed for long though.

What was the deal with the bootloader again: I show 1.0.1.6. in the 68U is that good or bad, e.g. promising for OC?

 

[RMerlin]

83C is perfectly normal for that CPU.

 

[kamaaina]

Thanks, glad to hear that. I just got worried because others with the AC56U reported much lower CPU temps, even though this is supposedly the same chip.

Well, my 56U is a switch now, that's all it does. It seems to function as an AP as well with the unsecured ASUS wifi settings, but there seems to be no way to get to the interface, clear the NVRAM, or get it into recovery mode. I tried the direct connection and manual 192.168.1.1 approach. No success. When connecting the internet through WAN port, no functionality. when wiring computer and internet through LAN ports it functions as a switch. something got nuked during the fw upgrade I guess. Any other magic tricks??

 

[RMerlin]

Thanks, glad to hear that. I just got worried because others with the AC56U reported much lower CPU temps, even though this is supposedly the same chip.

Well, my 56U is a switch now, that's all it does. It seems to function as an AP as well with the unsecured ASUS wifi settings, but there seems to be no way to get to the interface, clear the NVRAM, or get it into recovery mode. I tried the direct connection and manual 192.168.1.1 approach. No success. When connecting the internet through WAN port, no functionality. when wiring computer and internet through LAN ports it functions as a switch. something got nuked during the fw upgrade I guess. Any other magic tricks??

If the switch ports are working as a switch, then I suspect the FW is working. Otherwise, it would constantly reboot itself, or your power led would be flashing.

 

[kamaaina]

Have a second AC56U device now. Trying to OC. Followed the commands from post 1 but wonder if its working.

In sysinfo device still shows 800 Mhz for CPU. Device (re)booted successfully. Temperature went up though from 66 degrees C idle (stock) to 70/71 degrees idle now. Nothing connected, so no traffic. Wondering if that means the clock speed might have increased...

Any other way to check/test? Bootloader says 1.0.2.3 Firmware is Merlin 3.0.0.4.374.40.

temp went up to 73 degrees on idle. change the commands from 1200,800 to 1000,667 and see if that changes anything.

 

[RMerlin]

Have a second AC56U device now. Trying to OC. Followed the commands from post 1 but wonder if its working.

In sysinfo device still shows 800 Mhz for CPU. Device (re)booted successfully. Temperature went up though from 66 degrees C idle (stock) to 70/71 degrees idle now. Nothing connected, so no traffic. Wondering if that means the clock speed might have increased...

Any other way to check/test? Bootloader says 1.0.2.3 Firmware is Merlin 3.0.0.4.374.40.

temp went up to 73 degrees on idle. change the commands from 1200,800 to 1000,667 and see if that changes anything.

Check the bogomips:

cat /proc/cpuinfo

 

[Sky1111]

Have a second AC56U device now. Trying to OC. Followed the commands from post 1 but wonder if its working.

In sysinfo device still shows 800 Mhz for CPU. Device (re)booted successfully. Temperature went up though from 66 degrees C idle (stock) to 70/71 degrees idle now. Nothing connected, so no traffic. Wondering if that means the clock speed might have increased...

Any other way to check/test? Bootloader says 1.0.2.3 Firmware is Merlin 3.0.0.4.374.40.

temp went up to 73 degrees on idle. change the commands from 1200,800 to 1000,667 and see if that changes anything.

BogoMIPS: cat /proc/cpuinfo
non-OCed will show ~1600, anything above is your gain

 

[kamaaina]

Guys, thank you so much for your help and guidance. I found this parallel thread, started fresh and made some progress via telnet connection.

I managed to overclock my RT-AC68U to 1000,800 and the cat info shows MIPS accordingly. Rebooted and it shows in sys tools info as well, plus VPN speed has greatly improved. Will leave it stable now to see what the temperature is doing. But looks like this one is OC at 1Ghz for now.

Processor : ARMv7 Processor rev 0 (v7l)
processor : 0
BogoMIPS : 1998.84

processor : 1
BogoMIPS : 1998.84

Features : swp half thumb fastmult edsp
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x3
CPU part : 0xc09
CPU revision : 0

I am puzzled though because the same approach is not working with the RT-AC56U. I tried the commands in the GUI shell, I tried it via telnet. The difference I am aware of is the CFE boot loader. The 68U is on 1.0.1.6 or so, the 56U is on 1.0.2.3. Maybe that's what's blocking it. FW wise they are almost the same, the 68U is on .39 and the 56U on .40 Merlin.

When I type set clock via telnet and don't reboot it will show the changed speed in the GUI shell after a refresh, however, Bogo MIPS remains unchanged at ~1600. I tried that with 1000 and 1200 and it shows, yet does not seem to do anything. Once I commit and reboot it's all back to normal, will show 800 again and MIPS stay at ~1600 anyway.

I do have a second 56U here but flashed it with Tomato (Shibby) earlier, was hoping there might be an overclock setting like for the E3000, but there isn't. Seems to be stable but I can't see the CFE version now. Will flash that one back over the weekend and see if it has a different boot loader, maybe that's the issue. Any other thoughts otherwise? Thanks!
- -
Update: Flashed the second 56U back to Merlin.39, same boot loader 1.0.2.3 Does not respond to over clock. Speed initially displayed in system shell in the Merlin GUI but after reboot everything is lost, plus bogomips stays at 1600. Is this a known "lock" with this CFE? Any way to revert to a boot loader that works? I cannot do serial connections, but if it's a few telnet commands that can be copy/pasted I would try one. The AC68U is doing fine. 24h later at 1000Mhz and temperatures are the same, lower 80C. Not much traffic though, but still a good sign I guess.

 

[kamaaina]

Have the AC68U running at 1200 mhz now, it's been fine for 48h and temperatures around 85C with OpenVPN client running for all router traffic. Too afraid to try 1400 for this one without extra cooling.

Put my R7000 at 1400 mhz and the CPU is at 60C. This one is running DD-WRT right now. I guess it has better cooling build in. OpenVPN client gets 35-40 Mbit download speed with PIA, very nice.

I wish I could tune the AC56U as well. As far as I know they all have the same chip inside, AC56U, AC68U, and Netgear R7000.

 

[RMerlin]

Have the AC68U running at 1200 mhz now, it's been fine for 48h and temperatures around 85C with OpenVPN client running for all router traffic. Too afraid to try 1400 for this one without extra cooling.

Put my R7000 at 1400 mhz and the CPU is at 60C. This one is running DD-WRT right now. I guess it has better cooling build in. OpenVPN client gets 35-40 Mbit download speed with PIA, very nice.

I wish I could tune the AC56U as well. As far as I know they all have the same chip inside, AC56U, AC68U, and Netgear R7000.

The R7000 has a different SKU which defaults to 1 GHz, while the SKU used by Asus defaults to 800 MHz.

 

[Sky1111]

Plus Netgear seems to have a better cooling solution too...

IMO very rare specimens of AC56U can reach 1400 and beyond, and it's not a cooling issue - simply anything beyong 1GHz is pushing the limits of BCM4708. We cannot play with voltages and fine tune clocks like we do on normal overclocked PC, and remind you my own experience - at the attempt to reach 1400, my AC56 bricked and luckily I got it RMAed.

Your R7000 is a different beast (a little bit). Given the fact that it does not have ASUS' fragile bootloader, you might be able to hit 1400, but I am not sure as I personally never tried.

 

[Sky1111]

By the way, what FW are you running on you R7000? Kong's?

 

[RMerlin]

Your R7000 is a different beast (a little bit). Given the fact that it does not have ASUS' fragile bootloader, you might be able to hit 1400, but I am not sure as I personally never tried.

Asus's bootloader is actually Broadcom code. There's a good chance the R7000 shares the same CFE code.

 

[kamaaina]

Oh sorry guys, I kind of dropped out here. Guess I need to change the notification settings. Bricked the R7000 in between and redid the network a few times and tried different fw.

At this time I have Tomato on the R7000 and it seems to run stable at 1400 mhz. I say "seems" as I haven't been running longer than 5-7 days at a time yet as always changing something. Kong posted he tested past 1200 and it does not pass performance tests on the router, but for an average home user like myself it seem to do everything needed just a little faster at 1400 just fine. I had a Kong build before but had issues with the OpenVPN client. Tomato seems to run it stable, but there are others pieces in Tomato not fully working yet, e.g. QoS n/a. The router did 1400 with Kong fine as well, and the VPN problem happens with people on stock speed as well.

 

[aeolius]

Overclocking the AC56U

When overclocking the AC56U on the newer CFE 1.0.2.3 you must set the clock for the cpu to what you want it and the memory to 533, if you try to set the memory to anything else it will revert everything upon reboot.