QoS for Upstream Only?

[klaxian]

TL; DR: Can I enable Adaptive QoS on the upstream only? Will setting a very high download value accomplish this?

I get about 500mpbs down and 25mbps up with my internet connection. When I max out the download speed, CPU usage on my RT-AC68R (800MHz) reaches about 80%. I am not using any features that tax the CPU or disable CTF. Unfortunately, if I enable Adaptive QoS, CPU usage on my RT-AC68R hits 100% and my download speed maxes out at 285mbps. The UI reports that CTF is active whether or not Adaptive QoS is enabled. I am using firmware 384.14_2 and I have performed a full M&M reset.

Is this CPU usage normal for my router with these speeds? I would prefer to enable Adaptive QoS to ensure fluid gaming and VoIP while all my users are taxing the WAN. However, it's only really important for the upstream. Is it possible to enable QoS for uploads only while leaving downloads alone? I realize if I set a very high value for download speed, QoS will probably never affect the speed, but will it stress the CPU regardless?

Thanks.

 

[L&LD]

QoS is CPU heavy. After enabling it and waiting 15 minutes to an hour for it to stabilize itself, did you reboot the router and then test again after it was idling for an additional 15 minutes?

Setting a very high value for 'down' will affect only the 'up' (relative to your ISP speeds, of course), but still at the cost of CPU cycles.

When I upgraded my 'classic' dual-core 800MHz RT-AC68U to a dual-core 1.4GHz RT-AC3100 I could fully use my 1Gbps up/down a (symmetrical) connection. But not with QoS enabled.

Are you measuring over WiFi or wired? Either way, I would recommend a router upgrade to at least an RT-AC3100 or better yet, an RT-AC86U instead.

 

[bbunge]

TL; DR: Can I enable Adaptive QoS on the upstream only? Will setting a very high download value accomplish this?

I get about 500mpbs down and 25mbps up with my internet connection. When I max out the download speed, CPU usage on my RT-AC68R (800MHz) reaches about 80%. I am not using any features that tax the CPU or disable CTF. Unfortunately, if I enable Adaptive QoS, CPU usage on my RT-AC68R hits 100% and my download speed maxes out at 285mbps. The UI reports that CTF is active whether or not Adaptive QoS is enabled. I am using firmware 384.14_2 and I have performed a full M&M reset.

Is this CPU usage normal for my router with these speeds? I would prefer to enable Adaptive QoS to ensure fluid gaming and VoIP while all my users are taxing the WAN. However, it's only really important for the upstream. Is it possible to enable QoS for uploads only while leaving downloads alone? I realize if I set a very high value for download speed, QoS will probably never affect the speed, but will it stress the CPU regardless?

Thanks.

While I do not have a 500 meg connection I have noticed that my AC66U_B1 (basically the same hardware as the AC68), with QOS enabled, does very well using sfq and the upload/download bandwidth set to 95% of the WAN rated speed (100 meg fiber). CTF is enabled. When I use fq_codel the RAM and processor usage goes up and I see no appreciable gain in buffer bloat and a slight decrease in performance. Does not make sense as fq_codel is supposed to improve QOS.
Am sure others will slam this but it is my honest observation. As for the recommended upgrade it is your choice but I am suspicious of the reliability of the AC86U. With the newer Merlin firmware I have had almost no issues, after my minor tweaks, with the home AC66U_B1 or the AC68U's in an office environment.