Disapointed with RT-AC5300 CPU - Where to go from here?

Qwerts

New Around Here
Hi. I upgraded from my AC68U last year and have been pretty happy with my AC5300 until this past week when I got my Synology NAS. During data transfers, albeit huge transfers, CPU 1 runs at near 100% (while CPU 2 runs at 2%) subsequently halting all other activity wireless and wired on the network. The network is small and even with one PC trying to access the internet it's impossible during large NAS population transfers. I should say that wireless transfers to the laptop from the NAS had CPU usage near 100% but wired transfers to the laptop from the NAS had CPU usage around 50-60% but even at that range it still killed concurrent wired PC internet access. Thinking the AC5300 was pretty future proof I'm disappointed with the CPU boging down as it is, is there a recommendation to get something that can handle NAS transfer activity and not render the network useless? Oh and yes I could limit the transfer speeds with QOS but speeds are only about 25-32MBs anyway, in no way blistering so I wouldn't want to slow them down anymore. Maybe my AC5300 settings are whack so open to suggestions.
Thanks.
 

Qwerts

New Around Here
Thanks for the reply. Did not know that about QoS, I thought you could throttle any traffic connected to the router. Shows I never used it!. Regarding spreading devices over the 2 channels, thats the thing, only one wireless device and one wired device is active and the NAS takes complete control of the bandwidth and CPU. Router CPU will be at 0 usage and when a sync is initaited on the laptop wirelessly the CPU remains steady at 98% and around 50% if I connect a cable directly to the router.
 

ColinTaylor

Part of the Furniture
That does sound wrong.

It's possible that the wired to wireless data transfer will consume CPU, but it's not normally large enough to cause a problem.

The wired (laptop) to/from wired (NAS) transfer problem is more telling. That ought to be a direct data transfer between the switch ports. As such it should be consuming zero CPU resource on the router. The only scenario I can think of where you see this behaviour is if you're using the router's WAN address (or WAN DNS name) to access the NAS (with port forwarding set up) which would mean the data is sent to the router's WAN port and then looped back (NAT loopback) to the NAS.
 
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Qwerts

New Around Here
That does sound wrong.

It's possible that the wired to wireless data transfer will consume CPU, but it's not normally large enough to cause a problem.

The wired (laptop) to/from wired (NAS) transfer problem is more telling. That ought to be a direct data transfer between the switch ports. As such it should be consuming zero CPU resource on the router. The only scenario I can think of where you see this behaviour is if you're using the router's WAN address (or WAN DNS name) to access the NAS (with port forwarding set up) which would mean the data is sent to the router's WAN port and then looped back (NAT loopback) to the NAS.

Yes? This is the setup that Synology Quickconnect uses, (I believe). I didn't want to use Quickconnect becasue I wanted to control my own security and instead set up a VPN on the router to tunnel the traffic from the laptop via OpenVPN (to access while not on the LAN) but this was brutally slow. Quickconnect setup on the NAS asks for the ID which maybe relies on the WAN IP? Wouldn't it be smart enough to not use the public IP if it sensed a connection from the LAN? So is that whats happening? How do I get around that?

I'm sorry if this is turning into a tech thread, I'm a new member and don't want to break etiquette rules.
 

ColinTaylor

Part of the Furniture
Sorry, I don't know anything about Synology's software or what software you're using to transfer your data. But you'll need to configure things so that it doesn't use NAT loopback. Hopefully another forum member with Synology experience can chime in.
 

Tech9

Part of the Furniture
I also don't have Synology NAS, but I have an AC5300 router available. I may test what it can do LAN-WLAN on the weekend and what the CPU load is. The same CPU is used in AC1900P and it does >40MB/sec with older BCM4360 radios. I expect more from AC5300 with BCM4366.
 

Qwerts

New Around Here
I also don't have Synology NAS, but I have an AC5300 router available. I may test what it can do LAN-WLAN on the weekend and what the CPU load is. The same CPU is used in AC1900P and it does >40MB/sec with older BCM4360 radios. I expect more from AC5300 with BCM4366.
That would be great thanks! Who knows I may have defective hardware.
 

coxhaus

Part of the Furniture
There is no WAN to LAN QoS. There is only LAN to WAN. If you use a L3 switch then there is LAN to LAN QoS.

I don't care anything about wireless. You have it wrong.
 
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coxhaus

Part of the Furniture
I know why you'd say that but that is old-school thinking and not the case anymore.
How are you going to apply QoS to inbound traffic when the ISP is sending inbound traffic? There is no way you can have big enough buffers to change what the ISP is sending. Yes the ISP uses QoS but you can't change it. You can only change what you are sending out.
 

Maverick009

Regular Contributor
How are you going to apply QoS to inbound traffic when the ISP is sending inbound traffic? There is no way you can have big enough buffers to change what the ISP is sending. Yes the ISP uses QoS but you can't change it. You can only change what you are sending out.
QOS can be used both from WAN to LAN and LAN to LAN. It allows you distribute bandwidth not just from internet usage, but also for LAN based traffic such as NAS, or PLEX server, etc. The new way makes sense, as todays networks carry both traffic from the internet and local traffic from within a network, and you need a way to control that traffic. Now the equipment you use, may be limited. That I will not dispute, but with the right equipment and software, QOS is possible on both you WAN to LAN and LAN to LAN traffic.
 

Maverick009

Regular Contributor
Hi. I upgraded from my AC68U last year and have been pretty happy with my AC5300 until this past week when I got my Synology NAS. During data transfers, albeit huge transfers, CPU 1 runs at near 100% (while CPU 2 runs at 2%) subsequently halting all other activity wireless and wired on the network. The network is small and even with one PC trying to access the internet it's impossible during large NAS population transfers. I should say that wireless transfers to the laptop from the NAS had CPU usage near 100% but wired transfers to the laptop from the NAS had CPU usage around 50-60% but even at that range it still killed concurrent wired PC internet access. Thinking the AC5300 was pretty future proof I'm disappointed with the CPU boging down as it is, is there a recommendation to get something that can handle NAS transfer activity and not render the network useless? Oh and yes I could limit the transfer speeds with QOS but speeds are only about 25-32MBs anyway, in no way blistering so I wouldn't want to slow them down anymore. Maybe my AC5300 settings are whack so open to suggestions.
Thanks.
It may be a configuration setting. I would try to grab and update to the latest firmware. The router may support Merlin WRT and you could actually update to that for ASUS router and there were some fixes and updates that may fix the issue, as depending on the firmware you currently have, the decoder may not be proficient. Also I would check the NAS as well, and update to latest firmware, as that may be the issue, since you noticed it after adding the NAS. Last you could try a hard reset of the router and start out with default settings, test the transfer speed, and if hitting decent levels, then slowly set configurations as you see fit, trying after each and if you hit the issue again, you will know the setting that is causing it.
 

Maverick009

Regular Contributor
You guys are nuts, you cannot control inbound traffic with your little routers.
I said it matters on hardware. There are some consumer routers that can even in limited functionality and based on firmware. Secondly who says I have a little router? I can tell you my router is not small by any means
 

Qwerts

New Around Here
It may be a configuration setting. I would try to grab and update to the latest firmware. The router may support Merlin WRT and you could actually update to that for ASUS router and there were some fixes and updates that may fix the issue, as depending on the firmware you currently have, the decoder may not be proficient. Also I would check the NAS as well, and update to latest firmware, as that may be the issue, since you noticed it after adding the NAS. Last you could try a hard reset of the router and start out with default settings, test the transfer speed, and if hitting decent levels, then slowly set configurations as you see fit, trying after each and if you hit the issue again, you will know the setting that is causing it.

Have the latest firmware running and would really like to go with Merlin and was so close to pulling the trigger but that dang Asus app is so convenient to be able to change VPN settings on the go.

I went through all possible connections again and @ColinTaylor gave me an idea to check that I'm not sending traffic out of the network only to bring it back in i.e., using a WAN address. Starting all over testing the possible ways to connect; Quickconnect, Synology DNS VPN, OpenVPN using No-IP, Direct IP, VPN on NAS, VPN on router I really just settled on Quickconnect for simplicity. Yes OpenVPN on the router is obviously the best choice for security but is the absolute slowest so isn't worth the hassle to have to fire up the connection on the laptop to initiate file sharing to the NAS. Synology's Quickconnect is more of a Dropbox like experience which is what I was looking to replace because of my tin hat privacy concerns with DB. Quickconnect in the end solved the CPU issue because the bandwidth it processes isn't bogging down the CPU so I guess it's a win. Convenience, reduced CPU load, better cross platform seamless access at the expense of speed, oh well.

Thanks for the help on the topic and the entertainment of the sidebar QoS banter lol!
 

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