AC5300 performance, high CPU (or not), and AiMesh

[snovvman]

Edit: If you are on Version 3.0.0.4.384.81622 dated 2020/02/21, please check to see if your 5300 has high CPU utilization. Thanks.


Hi,

My Internet connection speed, when wire-connected, is 450 to 550 Mbps. My current setup is one AC5300 (first gen) and two AC88U AiMshed. The AC5300 is the controller. All are on the latest firmware. The AC5300 is in AP AiMesh mode. I have a separate firewall and router. There are no USB connected devices. The Ethernet connection to the switch is 1GB.

5Ghz. I have noticed that when I am near and connected to the 5300, my throughput is around 120 Mbps. When connected to the AC88U, it is around 200+ Mbps. Sometimes 5300 would show slower than 120.

I have not been able to track down the performance issue, although when the 5300 was running as a stand-alone, its performance was never stellar. I came upon a post that talked about CPU utilization. When looking, I noticed that the 5300's CPU is essentially pegged at all times. I then SSH'd and ran a "top", only to find that top reported that the CPU (as far as I can understand) is loafing along. The two images were taken within a few seconds of one another.

A few questions:
1) Is the CPU graph showing below normal?
2) Why does there appear to be a discrepancy between the graph and SSH top?
3) Is there anything I should do about 1 and 2?
3) Are there any known performance issues with 5300 that can be resolved? My real goal is to improve the 5300's wireless speed.

I would appreciate any guidance.

 

[OzarkEdge]

Hi,

My Internet connection speed, when wire-connected, is 450 to 550 Mbps. My current setup is one AC5300 (first gen) and two AC88U AiMshed. The AC5300 is the controller. All are on the latest firmware. The AC5300 is in AP AiMesh mode. I have a separate firewall and router. There are no USB connected devices. The Ethernet connection to the switch is 1GB.

5Ghz. I have noticed that when I am near and connected to the 5300, my throughput is around 120 Mbps. When connected to the AC88U, it is around 200+ Mbps. Sometimes 5300 would show slower than 120.

I have not been able to track down the performance issue, although when the 5300 was running as a stand-alone, its performance was never stellar. I came upon a post that talked about CPU utilization. When looking, I noticed that the 5300's CPU is essentially pegged at all times. I then SSH'd and ran a "top", only to find that top reported that the CPU (as far as I can understand) is loafing along. The two images were taken within a few seconds of one another.

A few questions:
1) Is the CPU graph showing below normal?
2) Why does there appear to be a discrepancy between the graph and SSH top?
3) Is there anything I should do about 1 and 2?
3) Are there any known performance issues with 5300 that can be resolved? My real goal is to improve the 5300's wireless speed.

I would appreciate any guidance.

Have you reset the 5300 lately and configured from scratch?

The pegged CPUs seem abnormal, especially for an AP doing nothing in particular.

With a little experience, you can setup a router and feel whether or not something is not right. I would perform a fresh install as a standalone router and make that call.

I know that sounds like dumb advice, but I'm trying to start somewhere.

OE

 

[L&LD]

@OzarkEdge I completely agree with your post above, but I'm sure we'll now both be mocked for the way the network/router feels.

 

[snovvman]

Thank you both. It was not that long ago that this network was setup. I will reset if I must, but I am curious--does the screen shot in my OP provide any clue as to what might be going on? Are there any other ways of troubleshooting before I have to down the painful path of resetting? Again, thanks.

 

[OzarkEdge]

Thank you both. It was not that long ago that this network was setup. I will reset if I must, but I am curious--does the screen shot in my OP provide any clue as to what might be going on? Are there any other ways of troubleshooting before I have to down the painful path of resetting? Again, thanks.

The CPU pic is abnormal to me. @RMerlin could probably comment on the details listed in the second pic.

A reset is recommended after a new firmware install. If you've upgrade the firmware and have not reset, a reset is a first step. It's not that difficult. If you reset the 5300 and the CPUs are pegged, then something is wrong, yes?

Edit: You might also want to first re-flash the latest 5300 firmware. Reset it, reflash it, reset it, configure it.

OE

 

[jazzer]

Hi,

My Internet connection speed, when wire-connected, is 450 to 550 Mbps. My current setup is one AC5300 (first gen) and two AC88U AiMshed. The AC5300 is the controller. All are on the latest firmware. The AC5300 is in AP AiMesh mode. I have a separate firewall and router. There are no USB connected devices. The Ethernet connection to the switch is 1GB.

5Ghz. I have noticed that when I am near and connected to the 5300, my throughput is around 120 Mbps. When connected to the AC88U, it is around 200+ Mbps. Sometimes 5300 would show slower than 120.

I have not been able to track down the performance issue, although when the 5300 was running as a stand-alone, its performance was never stellar. I came upon a post that talked about CPU utilization. When looking, I noticed that the 5300's CPU is essentially pegged at all times. I then SSH'd and ran a "top", only to find that top reported that the CPU (as far as I can understand) is loafing along. The two images were taken within a few seconds of one another.

A few questions:
1) Is the CPU graph showing below normal?
2) Why does there appear to be a discrepancy between the graph and SSH top?
3) Is there anything I should do about 1 and 2?
3) Are there any known performance issues with 5300 that can be resolved? My real goal is to improve the 5300's wireless speed.

I would appreciate any guidance.



View attachment 21738

View attachment 21739

I have been facing the same high CPU usage issue since upgrading to the latest AC5300 firmware sometime last week. Version 3.0.0.4.384.81622 (2020/02/21)

My current setup is an AiMesh with AC5300 as a Router + 1x Ac5300 node + 1x Ac86 node.
I’ve been having other types of wifi dropping issue (won‘t be discussing here to avoid commingling issues), but never noticed a slow down caused by high CPU usage until the recent firmware update.

And yes, I have done a complete reset of the AC5300 the first time I noticed this issue. Reloaded firmware manually (downloaded from website), reset again and then manually re-configured. One day later, high CPU again.. caused by mtdblock3 *fustrating!*

Googling mtdblock3 it seems related to the rootfs containing the firmware ?

Struggling to figure it out, I have now reverted both the AC5300 units to the previous firmware manually, and at the same time swapped my units (node<>route) just in case its a hardware problem. Now I no longer have the high cpu usage for a few days.

Could there be an issue with the latest firmware?
It seems to have the smallest file size of all firmware versions.

 

[snovvman]

I have been facing the same high CPU usage issue since upgrading to the latest AC5300 firmware sometime last week. Version 3.0.0.4.384.81622 (2020/02/21)

Struggling to figure it out, I have now reverted both the AC5300 units to the previous firmware manually, and at the same time swapped my units (node<>route) just in case its a hardware problem. Now I no longer have the high cpu usage for a few days.

I too, am on 3.0.0.4.384.81622. Thanks for reporting your experience and work already done. I was going to reset/reflash/rebuild this weekend but may hold off for now. I am curious if others with the same firmware are seeing the same. I will see about editing the subject of the OP to see if others will report.

///

Edit: I guess I can't change the title of the post. I did add a line requesting experience reports for those who are on the latest build.

 

[OzarkEdge]

I too, am on 3.0.0.4.384.81622. Thanks for reporting your experience and work already done. I was going to reset/reflash/rebuild this weekend but may hold off for now. I am curious if others with the same firmware are seeing the same. I will see about editing the subject of the OP to see if others will report.

I would downgrade and wait it out. It sounds like a firmware defect that is impacting your WiFi throughput.

OE

 

[snovvman]

I would downgrade and wait it out. It sounds like a firmware defect that is impacting your WiFi throughput.

OE

This has gotten me thinking about moving to Merlin. I see that the latest stable Merlin release is dated prior to the current Asuswrt. As a related question, would I be able to flash the older-dated Merlin over the Asuswrt without having to use Rescue Mode? Curiously, were I to be on Merlin and want to flash a newer/older Asuswrt, could I just flash over? I realize that a post-flash reset is important. Thanks for sticking with this thread.

 

[OzarkEdge]

This has gotten me thinking about moving to Merlin. I see that the latest stable Merlin release is dated prior to the current Asuswrt. As a related question, would I be able to flash the older-dated Merlin over the Asuswrt without having to use Rescue Mode? Curiously, were I to be on Merlin and want to flash a newer/older Asuswrt, could I just flash over? I realize that a post-flash reset is important. Thanks for sticking with this thread.

It does make sense to rely on Asuswrt-Merlin releases to vet stock Asuswrt releases.

However, I have no experience using Asuswrt-Merlin. I can only refer you to here:
https://github.com/RMerl/asuswrt-merlin.ng/wiki/Installation

And the home site:
https://www.asuswrt-merlin.net/

OE

 

[Grisu]

You can always change between stock and Merlin, no need for rescue as long as it will upload the file.
After moving from one to the other a reset with initialize is recommended, but even that may not be needed if everything is running fine.
For major jumps (like more then 3 releases) you should do a reset.
Just do it, you will see and if strange problems occour you still can do the reset with manual setup.
Your router wont bite!

I have been facing the same high CPU usage issue since upgrading to the latest AC5300 firmware sometime last week. Version 3.0.0.4.384.81622 (2020/02/21)

I would test the router for corona virus!
Firmware comes from China (Taiwan) and is probably infected!!!

 

[snovvman]

Update: I flashed from Asus 3.0.0.4.384.81622 (2020-02-21) to Merlin 384.15 (2020-02-08). Even though Merlin was dated slightly earlier, it flashed over the Asus firmware fine. I have not done a reset. With the Merlin firmware, the CPU is well below 3%. I also got a download of 417 Mbps from an iPhone.

After reading Merlin's advisory about AiMesh, I decided to leave the nodes on Asus factory. So far, everything is running great. Thanks for all the help!

 

[jazzer]

Update: I flashed from Asus 3.0.0.4.384.81622 (2020-02-21) to Merlin 384.15 (2020-02-08). Even though Merlin was dated slightly earlier, it flashed over the Asus firmware fine. I have not done a reset. With the Merlin firmware, the CPU is well below 3%. I also got a download of 417 Mbps from an iPhone.

After reading Merlin's advisory about AiMesh, I decided to leave the nodes on Asus factory. So far, everything is running great. Thanks for all the help!

That's good to hear! I am tempted to give Merlin firmware a go.

I wonder if it might solve an aimesh routing issue I have, where devices that roam from one node to another become unreachable to devices on other nodes.

As an example, my NAS is connected to a aimesh node, when my iPhone roams from that node to the main router, I am no longer able to reach the NAS. Internet works fine & roaming back will immediately make it reachable again.

This seems to be a roaming issue, because if I disconnect my iPhone for ~ 10 mins, and reconnect it directly to the main router, it can reach the NAS connected on the node. But roaming to it and back, will make it unreachable again.

Hope it doesn't sound too confusing, but does anyone else have this issue?

 

[OzarkEdge]

I have not done a reset.

At least you know your next step.

OE

 

[OzarkEdge]

That's good to hear! I am tempted to give Merlin firmware a go.

I wonder if it might solve an aimesh routing issue I have, where devices that roam from one node to another become unreachable to devices on other nodes.

As an example, my NAS is connected to a aimesh node, when my iPhone roams from that node to the main router, I am no longer able to reach the NAS. Internet works fine & roaming back will immediately make it reachable again.

This seems to be a roaming issue, because if I disconnect my iPhone for ~ 10 mins, and reconnect it directly to the main router, it can reach the NAS connected on the node. But roaming to it and back, will make it unreachable again.

Hope it doesn't sound too confusing, but does anyone else have this issue?

Consider starting your own thread.

OE

 

[COBOL-Coder]

The CPU pic is abnormal to me. @RMerlin could probably comment on the details listed in the second pic.

A reset is recommended after a new firmware install. If you've upgrade the firmware and have not reset, a reset is a first step. It's not that difficult. If you reset the 5300 and the CPUs are pegged, then something is wrong, yes?

Edit: You might also want to first re-flash the latest 5300 firmware. Reset it, reflash it, reset it, configure it.

OE

 

[COBOL-Coder]

This will sound dumb I'm sure but I've heard the term "Reset" many times but have never heard exactly what that means for sure. In 30 plus years in the IT industry, working on many platforms from archaic IBM mainframes to Hi-End Client Server networks that term reset came to mean many things. With regards to the AC5300 in discussion, do you simply mean putting a pin in a small hole (or pressing a button in the back) marked reset and let it go through it's cycle? Is there anything else implied by that term, in addition to the above, as used in this discussion? Thanks…

 

[OzarkEdge]

This will sound dumb I'm sure but I've heard the term "Reset" many times but have never heard exactly what that means for sure. In 30 plus years in the IT industry, working on many platforms from archaic IBM mainframes to Hi-End Client Server networks that term reset came to mean many things. With regards to the AC5300 in discussion, do you simply mean putting a pin in a small hole (or pressing a button in the back) marked reset and let it go through it's cycle? Is there anything else implied by that term, in addition to the above, as used in this discussion? Thanks…

Notice your extra empty post above. You've done a few of these, so I would review your reply method.

This post discusses router reset: https://www.snbforums.com/threads/faq-nvram-and-factory-default-reset.22822/

OE

 

[doeboy]

Quick question, Can I run Merlin firmware while in AP mode? I have the AC5300 in AP mode and hardwired to my AX11000, which is connected to my modem. I know I cannot run Merlin in AiMesh mode, but can it be ran in AP mode. (AiMesh mode doesn't allow for the 2nd 5ghz band to be used when using ethernet as a backhaul, so I changed it to AP mode and now can utilize all 3 bands on both routers.)

 

[Grisu]

You can use Aimesh on Merlin since 384.13!
And you can use Merlin in AP mode, he only adds some nice features based on what comes from stock.

Hope it doesn't sound too confusing, but does anyone else have this issue?

There are some postings about problems after roaming to master router (no internet), going back to node everything ok again, seems to be unsolved for some.