Hello,

I just flashed BB 14.07 to a TP-Link Archer C7 v.2.0 (AC1750) and I am experiencing *very* slow wifi performance on the clients. Its like down: ~8mbps up: 8mbps  .... while with stock fimware it was down: 60 mbps up: 15mbps. I am measuring with speedtest.net app and website. Tried nearly all encryption modes and also without encryption. 2,4ghz only - as I cant test 5ghz yet.

Anyone else here have same experience with this router and OpenWRT?

Regards,
CHERRY*

Archer C7 Wikipage: http://wiki.openwrt.org/toh/tp-link/tl-wdr7500

(Last edited by CHERRY* on 3 Jul 2015, 16:36)

Definitely haven't seen that. What client device?

Why don't you try CC rc2?

http://downloads.openwrt.org/chaos_calm … x/generic/

Cheers.

(Last edited by loyukfai on 14 Jun 2015, 16:00)

Android Tablet (2,4ghz) and recently iPad Air, iPad Mini

I havent tried CC rc2, as I was afraid I could *brick* the device. I hope i can give it a try in the next days, if its safe to flash it. I heard, that v.2.0 comes with a newer chip-model ... maybe thats an issue for the firmware? Someone made some testing with v2 and CC: https://forum.openwrt.org/viewtopic.php?id=53703

Wait for rc3 unless you are comfortable installing the webgui from the command line. The v2.0 does have a newer chipset for the 5GHz band, but 2.4GHz is the same. The 2.4GHz wifi driver is roughly unchanged from much older models and is quite stable. There was one bug that seemed more common with android devices that would occasionally lock that wifi band. This has been fixed in CC.

Is it very risky to try trunk CC rc3 on the Archer C7 v2.0 ? Whats the chances to brick the device when using binary from official download site?

When will Chaos Calmer rc3 be available?

Do you have more information on that bug? Is it possible there is also a bug when measuring the speed with "speedtest.net" app on Android or iOS?

(Last edited by CHERRY* on 19 Jun 2015, 10:45)

rc3 will be out when it's ready Unless they go right to a final version...

Off the top of my head, I don't have any info on the android bug. It shouldn't impact speedtest

ok i tried CC 15.05 rc2 with manual luci installation. Wifi 2,4ghz android speedtest.net app ... Down: 16mbps up: 15mbps. With stock i get > 20mpbs. Did I miss anything or why is this so slow wifi speed? Do I need to install any more software or packets?

(Last edited by CHERRY* on 3 Jul 2015, 16:33)

Please try to isolate whether the problem really is with wireless, or perhaps elsewhere.  I'd suggest installing & starting iperf on the router (or another LAN-attached device, which would be better if you want to compare to stock) and using an iperf client on your Android/iOS device to verify what throughput you can achieve on wireless.  Speedtest is quick and easy, but there are so many variables involved that makes it inappropriate as a tool to troubleshoot wireless throughput with.

(As an aside, I don't think there's any relation between your issue and the one in the link you posted.  That person was mostly concerned with why he was getting "only" 500Mbps on his 5 Ghz radio (802.11ac.)  You're not using 5 Ghz (ath10k driver in the C7's case) and you're not stuck with a "ceiling" of 500Mbps.

Other possible variables you should try eliminate:
-- the stock firmware may have used a different wireless channel, and that there is interference/contention on the wireless channel OpenWRT is currently set to use
-- the stock firmware may have used a 40 Mhz wide channel, which would also impact results.  Ensure that you have like-for-like setups (apologies if that's what you did, but your post does not provide enough information to be sure.)

Ok, I finally was able to do some iperf tests and it seems that the bare wireless-speed is nearly the same - still the performance with Internet speed is horrible slow on WiFi speedtests. So the problem might not be the wifi controler itself ... But what could slow down the performance that much? As I said its a fresh install.

@Atom: Do you have more ideas? please

(Last edited by CHERRY* on 12 Jul 2015, 19:22)

I have never been able to hit my broadband speed over WiFi with any OpenWRT powered router.

I have no idea why either, when iperf shows WiFi can perform well above my broadband speed.

Well, if the connection in your signature is still valid (70Mbps), then I'm somewhat surprised, because that's not much more than I have (50Mbps). For me it makes no difference, if a client is wireless or not. They all achieve full speed on my internet connection. Even one of my laptops that only has a one stream wifi-n card.

My router is an Archer C7 v2 as well.

I can only assume its some odd MTU issue, or something else specific about my ISP that is causing it.

I have had the same ISP all the time I have had VDSL so haven't been able to see if it makes a difference.  My router was running OpenWRT but now its on pfSense, and it makes no difference at all on WiFi.

  Its not a huge problem, if I need speed I just use wired, but its irritating not knowing why its happening.

UPDATE
Just got a new laptop with a built-in Intel AC 3160 1x1 card and proper SATA HDD (so no longer bottlenecked by the ASUS T100 only having an eMMC) and its hitting 38.8MB/s right now copying video files from my NAS to the internal HDD.

I think that's pretty darn amazing but makes it even more weird that at the same time my broadband caps around 5MB/s on the same WiFi.

UPDATE 2
Swapped the card for an Intel AC 7260 2x2 card and surprisingly only peaking at 51MB/s so far, averaging around 46MB/s. 

However, on the large files I tried it does seem to stick to a minimum of 35MB/s whereas the 3160 would drop to 25MB/s and just generally seemed to fluctuate more in the same location. 

Through a thick brick chimney breast wall I'm still getting 28MB/s.  Unfortunately I forgot to test the 3160 here but I'm guessing it would have been a lot slower.

There is an additional 802.11n client connected compared to before though and my Note 4 still on 1x1 AC too, so those could potentially drag the speed down a little too.  An extra 10MB/s isn't terrible, but I did expect a bit more than that.

I have given up on iperf3 results as they seem completely wrong.  It clocked in 270Mbit max which is well below the 51MB/s real-world performance using SAMBA.