TP-Link Archer C2600 performance with 17.01.4

I just purchased an Archer C2600 and loaded 17.01.4 on the device. The device was very stable but all of my performance tests were topping out around 45-50Mbps on my 75Mbps AT&T U-Verse connection. I reverted my Archer to factory firmware and I’m getting 80Mbps running the same performance tests from the same devices. Previous threads seems to show that the C2600 is capable of good performance, so I’m wondering if there are some performance tweaks I’m unaware of or whether maybe I should try running an older version of LEDE.

Any insight would be greatly appreciated.

You don't really provide enough information to provide an answer, e.g. the most important one - do you measure wired or wireless traffic?

IPQ8064 is a rather fast SOC, its networking performance (the network interface between SOC and hardware switch) however is not quite on the same level, but it's still supposed to be much faster than your values (more in the 200-400 MBit/s region).

Sorry about the lack of info. I've measured this performance using both wireless and wired connections. I do not see any performance difference between the two, which leads me to believe this isn't a wireless issue and more of a hardware performance issue. However, as you stated, the chipset seems to be more than adequate for speeds much faster than I'm experiencing, so I'm wondering if there is any tuning that I should be looking to do.

I can't really comment upon IPQ8064, but I am using IPQ8065 (slightly newer and faster) myself on a 100/40 MBit/s connection with lots of headroom to spare (I never did a synthetic benchmark, as I know that my device is comfortably fast enough for the forseeable future and because setting up a reproducable/ local benchmarking environment including PPPoE and realistic NAT tests (many DNS lookups) isn't particularly trivial - with plain ethernet benchmarks not being representative for my usage).

While there are some performance improvements pending (qca8k), there aren't really any knobs necessary to tweak.

Thanks for the input.

At this point, there does seem to be some sort of knob I need to fiddle with, as the issue seems to point at the LEDE firmware and not the router hardware. The only time I don't get my max speeds is when I'm running the LEDE firmware. I can move my connection to my AT&T Gateway and achieve faster speeds. As I mentioned earlier, I also reverted to factory firmware on my Archer and achieved the same speeds as I did directly from the AT&T gateway.

I just found the LEDE post regarding the Smart Queue Management and am starting to wonder if there is some sort of QoS rate-limiter being applied. When doing my performance tests while running LEDE, the testing graphs were showing the typical TCP sawtooth pattern with apparent drops occurring around 50Mbps. This same TCP sawtooth pattern isn't present if I'm not running LEDE.

Unless you explicitly installed them yourself, no - neither the old qos-scripts nor sqm are preinstalled in the default firmware images (but easily installable via opkg). So that can be ruled out, at least if you didn't install a community build.

Ahh, that's very good information. Nope, didn't install any community build I'm aware of. The firmware I installed was:


So if there is no QoS installed by default, now I'm really baffled because something is clearly limiting the performance at 50Mbps. I saw another thread that said performance would be limited if WMM was disabled, but I had this enabled and that should only impact wireless performance.

I guess I need to understand the hardware better so that I have a better idea of where to start looking.

Thanks for your assistance.

Usually I'd suggest to test a recent snapshot (there has been considerable development for the ipq806x target since 17.01.x, combined with a newer kernel), but at the moment you'd probably want to wait until PR#1467: "mktplinkfw* fix invalid images due to wrong rootfs offset" gets merged into master before flashing a TP-Link device. Just be aware that snapshot builds don't have the webinterface (luci) preinstalled (opkg update && opkg install luci, if you have internet access via DHCP) and that snapshots are a moving target (rebuilt roughly daily). This can make installing some packages (kernel modules/ libraries) to older snapshot images a bit harder (impossible) than for release images.

Thanks again for the help. I'll try one of the recent snapshots and go from there. It sounds like you have good knowledge of this hardware and platform. Do you have any hints as to where I should be checking for drops, rate-limiters, performance issues, other than of course on physical and logical interfaces?

Did you manage to resolve the performance issues?
I also own TP-Link Archer C2600 and I too noticed not the best performance.

Has this issue been resolved? I have an ac2600 which i planned to put into service with Lede on it.

I'm wondering too if you fixed your issues. I'm only getting 50-67% of my max download speed on my C2600 running 17.01.4 r3560-79f57e422d.

Tested in OpenWRT 18.06 RC2 and the performance is really really bad.
I have a 600 MB. symmetric fiber, and I can't reach more than 60/70 MB. (tested with offload option on and off).
Later, tested with stock firmware and getting 600 MB.
Maybe in a near/far future will work fine (running LEDE/OpenWRT), but now, better stay in stock firmware.

Did you enable flow offloading?

I can conform. I tested TP-Link Archer C2600 with OpenWRT 18.06 and the performance was terrible. I returned to 17.01 because 18.06 with current form was impossible to use.

Yes (tested ON and tested OFF).

please delete this file from your root, reboot and retest

--> /etc/hotplug.d/net/20-smp-tune

Thanks !

Hi @r43k3n,

Which version of 17.01.XX are you using?
In your 17.01.XX version there is a good perfomance (in general terms)?

Thanks @blogic , I'll wait for next 18.06 version to test it again.
Now I'm running stock firmware again, testing Internet/Wifi performance.

Of course, I prefer using OpenWRT/LEDE firmware instead of stock firmware, but, Archer C2600 in my opinion is a "medium/high" home router, and now is running like a "low" home router using OpenWRT/LEDE. I know It's just a matter time, in some time will be working as "super-high" router with OpenWRT/LEDE :grinning::grinning::grinning:

@Klingon well with a positive test result, the fix would be part of the next 18.06 binary