Any way to overclock new RT-AC68U?

[Fenrir]

RT-AC68U_374.43_42E7j9527

 

[ColinTaylor]

Maybe it's just not possible with your hardware.

What do you get from this:

nvram get boardtype
nvram get clkfreq

 

[Fenrir]

board type- 0x0646
clkfreq- 1000,666

do you think the changes i made to the CFE would be overidding the script? or should the script override the CFE?
I'm contemplating trying to flash an older version of the CFE, just not sure what the chances of me bricking it are if i try that...

 

[ColinTaylor]

I'm contemplating trying to flash an older version of the CFE, just not sure what the chances of me bricking it are if i try that...

Don't. As far as I can tell your router has the 4709c0 CPU. If you flash an older CFE that isn't compatible with that processor you're probably screwed. It's not worth the risk for the minimal benefit overclocking might have IMHO.

 

[Fenrir]

yeah was just reading this https://www.snbforums.com/threads/bricked-rt-ac68u-when-downgrading-cfe.58231/
which seems like it answers my question unfortunately.

i have the option of swapping with my my old man as i gave him my old 68u a while ago.
begs the question am i better off with this new one, or overclock an old one haha

 

[john9527]

What bootloader (CFE) level is shown on the Tools page?

 

[Fenrir]

1.1.1.2

 

[Grisu]

What is written in CFE will replace NVRAM values after a reset to factory defaults. So it is dangerous to set it to 1400 if your router cant run it, you'll end up with a brick!
Changes in NVRAM will take place if you change it afterwards.
But newer (stock and maybe Merlin) firmwares will replace clock values with them from CFE every few hours, so you need a script to change it back every time to what you want it to be.
Only bogomips will tell your the truth how fast it really runs.
I can remember that I have seen this running with 100MHz (or very very slow) once, but sorry, cant remember what I did wrong to get this. Maybe set to a wrong value, inserted a blank after comma or equal sign or something like that.
Try it again 1200,666 with each command in one line. RAM-speed wont make it really faster, so stay at 666, possibly not every router is able to run 800 RAM-clock!
Allowed values for RAM-clk are 533/666/775/800 and 800/1000/1200/(1400) for cpu.

If you get it done in cfe you wont need any scripts or whatever, thats the great advantage, they are sticky.

 

[Fenrir]

sorry what do you mean with "each command in one line"?

Aslo are you suggesting this:
nvram set asuscfeclkfreq=1200,666 && nvram set asuscfecommit=1
nvram set clkfreq=1200,666 && nvram commit && reboot

 

[Grisu]

'&&' is adding more commands in one line, you can input each one seperately.
yes, thats what you could use (only if you know your router is able to run 1200MHz CPU!!!).

 

[Wallace_n_Gromit]

To overclock your 68U to 1200,800. This has been posted and verified many times. Works on ASUS and Merlin firmware.

nvram set asuscfeclkfreq=1200,800 && nvram set asuscfecommit=1
nvram set clkfreq=1200,800 && nvram commit && reboot

@ironclad has posted great info on safely OC'ing some RT-AC68U's. It includes a warning about setting the overclock in cfe. https://www.snbforums.com/threads/r...13-is-now-available.57860/page-21#post-510501

 

[Wallace_n_Gromit]

board type- 0x0646
clkfreq- 1000,666

I also tried the 2 commands that @ColinTaylor suggested and got:
board type- 0x0646
clkfreq- 800,666

But when I entered [cat /proc/cpuinfo | grep BogoMIPS] at command prompt I get:
BogoMIPS : 2798.38
BogoMIPS : 2798.38

It doesn't appear that [nvram get clkfreq] actually shows the current condition of the real clock speed. I suspect [nvram get clkfreq] just shows the content of either the CFE or NVRAM before you do any overclocking. I have Asus Bootloader (CFE) 1.0.2.0 on my 68U and have my 68U OC'ed to 1400Mhz

EDIT: Just an additional note. I have noticed following @ironclad's directions on safely overclocking my 68U an important caveat. When you power down your router and do a cold boot, the CPU runs at the original speed (in my case 800,666). When you do a reboot from the asuswrt GUI it will return to it's Overclocked speed (again, in my case 1400,800). I couldn't figure out until after some time why this behavior was manifesting itself (it's in the "safe" nature of ironclad's method--as a newbie I understand it) .

When I had overclocked the router to 1600Mhz it failed to start. I merely had to Power down/Press WPS and continue to press WPS for 30 seconds after powering up the router. It restarted at default settings. (had made backups of the router/JFFS config file(s), installed them and was as good as new)

Also the CPU speed showing on the TOOLS section of GUI is not necessarily accurate. Have to enter [cat /proc/cpuinfo | grep BogoMIPS] from the command prompt in ssh to know truely the CPU speed.

 

[JackFrost]

Is overclocking possible on AC68U hardware v3? Tried it but bogo mips goes to 100Mhz after OCing to 1200 and I had to revert to stock 1000Mhz.

 

[Wallace_n_Gromit]

Is overclocking possible on AC68U hardware v3? Tried it but bogo mips goes to 100Mhz after OCing to 1200 and I had to revert to stock 1000Mhz.

@Yota says that the newer 68U's have a newer CFE and CPU which will not allow OC'ing.
Overclocking underclocks BogoMIPS? Pls HELP! | Page 2 | SmallNetBuilder Forums (snbforums.com)

 

[JackFrost]

@Wallace_n_Gromit
thanks, that is the confirmation I was searching for.

 

[Lord Lovaduck]

I'm not suggesting that you do that. I just wanted to make sure you weren't running the CFE from a 68P. That has been known to severely cripple 68Us running newer firmware (regardless of clock frequency).
I just recently(a month or so ago) stepped my 68U main router to 1200 from 800 .

nvram get clkfreq
1200,800
cat /proc/cpuinfo | grep Bogo
BogoMIPS        : 2398.61
BogoMIPS        : 2398.61

Hi! Did you use active cooling for the processor? Or a large heat sink?

 

[Lord Lovaduck]

You have to create a one-line script.

When I tested it the VPN speed scaled fairly linearly with clock speed, so going from 800MHz to 1200MHz was just about worth the effort. The most you can increase the speed to is 1400MHz (assuming it's stable) so not a huge increase.

Hi guys....
I modified the NVRAM clock frequency to 1200,800 using SSH, soft rebooted and got the BogoMIPS increasing nicely! (to 2398.61 per core)
This technique apparently worked fine for my AC68U running Merlin 386.4.
I didn't change the CFE though... "I fear death"....
When running the little program below to push the CPU to 100% I don't see an increase in encryption speed... Am I looking at the right thing here?

while true; do openssl speed aes-256-cbc ; done;

Colin, how are you testing the VPN speed?
And are the Bogomips derived from a real CPU measurement? I ask because I didn't see any temperature increase nor an apparent speed increase in the router in my very limited testing...

 

[Ronald Schwerer]

Hi! Did you use active cooling for the processor? Or a large heat sink?

That issue happened to me and others many years ago. I was using a small USB fan to cool the router, but it wasn't a heat issue. There was/is some incompatibility using the 68P CFE on a 68U with the (then) current firmware. I haven't tried it since. I just overclock the 68U CFE and get the same BogoMIPS that you stated.

 

[Lord Lovaduck]

Thanks, Ronald! I have an old AC68U that I can afford to lose, so I decided to play some hacking with it.
I did test the overclocking and measured temperature... But I did the testing outside of the case, with the board horizontal on top of a table and free air flow. It ran just fine at (1200,800) and hardly getting to 75C. Around 55C without OC.
While running in the case before I OC it, usually ran at a steady 85C.
To make sure it won't overheat, and also to have some fun... I decided to make a franken case adding a fan from an Intel CPU. Will publish my contraption photos when I am finished.... I guess some would be tempted to revive an old unit adding some spice to it. Revive, or see it die a glorious death...

 

[Xcat2008]

I tried that already and nearly bricked my router haha
The new firmware has some sort of code that shuts the cpu down to 100Mhz when you try that

I apologize for digging up this Post.
When i do those commands also my router got really slow lol I guess blocks also to 100Mhz... But in the Web Browser shows 1200Mhz lol... The only fix to make it work normal again is SSH again and instead of 1200/800 change for the original values (1000 / 666).

My RT-AC68U data:
F/W Ver.: 3.0.0.4.380
H/W Ver.: E1

Any change of sucefull Overclock? For VPN performance and also ISP speed's, 1GB connecting getting around "only" 900 Mb.. And i'm sure is because if the CPU, while speedtest 2 cores at 100%.

Thanks