Posted: Thu May 30, 2019 14:01 Post subject: WRT1900ACS(ACV2) and slow WiFi with DD-WRT
Hi all,
I have a Linksys WRT1900 - the model number is WRT1900ACS but the FCC ID next to it is Q87-WRT1900ACV2. I know there is widespread confusion over these model numbers. I believe mine is a WRT1900ACV2. Is this correct?
I assume it must be as I have used the latest WRT1900ACV2 factory-to-ddwrt.bin firmware (ddwrt-linksys-wrt1900acv2-webflash.bin is the accompanying webflash from the same page in the router database). I guess if I had tried to use the WRT1900ACS firmware it wouldn't have worked?
Either way, I'm running WRT1900ACV2 firmware on it. The router has a broadband feed from my ISP router via ethernet. From my ISP router I get the maximum 60mb download on my current plan, either hardwired or through WiFi, no problem at all. I also get the same from the WRT1900ACV2 hardwired and WiFi on the stock Linksys firmware. Again I get the same 60mb from the WRT1900ACV2 with dd-wrt hardwired, but, as many many other threads have reported, I get pretty much exactly half that speed via WiFi. I have tested on multiple devices using speedtest.net.
I returned to the Linksys stock and everything is back to normal - 60mb. I then tried OpenWRT and everything is fine with that too.
In every case when testing, I am using firmware default WiFi settings. I have also tried almost every variance of WiFi settings within dd-wrt as recommended in many threads on here (network type, channel width etc), but I've not seen any WiFi speed/performance increase whatsoever.
Since this is purely limited to WiFi on dd-wrt, there has to be something in settings I am missing.
Posted: Fri May 31, 2019 17:38 Post subject: I had the same issue...
I had so much trouble that I stopped using the thing for a while.
Eventually I decided to wade back in as I don't like being beaten and these settings fixed it for me, at least on 5G.
Wireless Basic Settings Tab
5G
Wireless Network Mode: AC/N-Mixed
Channel Width: VHT80 (80 Mhz)
Wireless Channel: Auto
Extension Channel: Auto
2.4G
Wireless Network Mode: N-Only (2.4 Ghz)
Channel Width: Full (20 Mhz)
Wireless Channel: Auto
I just installed dd-wrt (was using openwrt) and I'm seeing this too on a WRT1900ACS v1. The 5gz seems to work ok but the 2.4 wireless is really bad on a tablet. I have a 400/20 cable connection and DD-wrt is giving me full speeds wired even with SFE disabled.
Wireless is another story. Tablet can do 30 down on openwrt and is only giving 5 with dd-wrt. Upload is full speed. I've been trying various wireless settings with no improvements.
I probably should have warned you about this when I replied to your OpenWRT to DD-WRT post sorry.
The reason I want to use DD-WRT is because its so much easier to configure a VPN than with OpenWRT, but this issue with DD-WRT is going to force me to move unless we can find a proper solution.
Thanks for the info Jonno1970, I'll give it a try later.
I probably should have warned you about this when I replied to your OpenWRT to DD-WRT post sorry.
The reason I want to use DD-WRT is because its so much easier to configure a VPN than with OpenWRT, but this issue with DD-WRT is going to force me to move unless we can find a proper solution.
Thanks for the info Jonno1970, I'll give it a try later.
Have you got a separate SSID for 2.4 and 5 GHz and have 5GHz set to wide (80)?
Are you certain the device you are doing the speed test on is AC not N?
It turned out it was a time/date problem. dd-wrt changed my time zone when I installed it. As soon as I changed that, I was getting full speed again.
Someone with more knowledge than me will have to explain why that would cause the wireless speed drop but changing it worked for me. Obviously, that won't be a solution for everyone but it's worth a check.
@ttowling - thanks for you response. It's a yes to all of your questions. I do get slightly faster speeds over 5GHz but nowhere near comparable to OpenWRT or Linksys stock.
@ellick - I'm glad someone has found a solution to slow WiFi but this did not make the slightest difference for me.
I have tried almost every combination of settings possible with this. I just don't know why it doesn't work. I have spent hour upon hour trying to get this to work but I've pretty much given up on DD-WRT now. It just doesn't work for me.
