Thanks JohnnySL. And so far all of my 2.4 devices are connecting fine with the ACS 1.0.0.168229 initial release firmware, so I'm staying put. The new firmware, which updated the wireless driver to v7.2.9.2 obviously still has some bugs. I will take it on faith that the "missing N" in the pulldowns is just a display glitch but I'm hoping people are reporting it to Linksys.
Linksys WRT-1900ACS Reviewed
- Thread starter RMerlin
- Start date
chadster766
Very Senior Member
It has been reported to Linksys engineering. Using the "Mixed" protocol and "Auto" channel width settings enables all protocols as a workaround.
sm00thpapa
Very Senior Member
On the ACS 5 Ghz wireless is there an AC only mode in the drop down menu? I'll be getting an ACS next week some time.
Sent from my iPad using Tapatalk
Sent from my iPad using Tapatalk
There is. These are the dropdown choices I currently get:
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sm00thpapa
Very Senior Member
Thanks for the pic. So I guess it needs to stay on mixed as long as you 5 GHz N devices. I may just leave this on AC only and cascade another router to handle all the N devices.
Linksys doesn't seem to be in a hurry to update this firmware, even though it is a step backwards from the initial release in terms of 2.4 connectivity and has major omissions from both the 2.4 and 5GHz pulldowns. The 1900ac firmware also hasn't been refreshed since last June.
sfx2000
Part of the Furniture
In 5GHz, you want to leave it in "Mixed" mode for best performance across all client specs...
11ac get's along quite well with 11n clients..
sm00thpapa
Very Senior Member
I just read the review again on the ACS. With the AC and ACS having the same 2.4Ghz wifi radio why the poor 2.4Ghz performance on the ACS?
sfx2000
Part of the Furniture
the marvell wifi driver is the suspect - much newer than the 1900acV1 that was tested some time back
sm00thpapa
Very Senior Member
Thanks for that info. I have the WRT1900AC and will be getting the ACS soon for testing. I had trouble with the 2.4Ghz band on the 1900AC and myself and Linksys could not figure out why. So now I'm thinking the ACS may even be worse. I'll have to see.
sfx2000
Part of the Furniture
That, and Marvell's implementation of TurboQAM leaves a lot to be desired - quick tip here...
Put the V1/V2 2.4Ghz radio into "B/G/N only" mode, and the range/performance comes back nicely... the ACS has a WebUI glitch that doesn't allow this.
sm00thpapa
Very Senior Member
Thanks dude. I will have to try this. Hope a new firmware upgrade can fix both routers.
sm00thpapa
Very Senior Member
Dude your a blessing! I went from N only to mixed and my wifi speed increased by over 50Mbps on the 2.4Ghz band. Thank you so much.
sfx2000
Part of the Furniture
FattysGoneWild
Regular Contributor
What would be the difference and best approach compared setting it to "Mixed"? Its not the same thing? I personally have a WRT1900AC V1. But, I have it set to N only and 20mhz. Tons of neighbors around using 2.4GHz. So, 40MHz is out. But, I seen a few posts up wireless improving on the 2.4GHz if set to b/g/n mode only? It was advised setting it to that but the member put it to mixed and still seen better results? Confusing. I have no dedicated "G" devices. I know they use N. The setting advised and better performance. Perhaps a glitch in the firmware or something when using just N?
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sfx2000
Part of the Furniture
It's complicated...
First - N-Only Mode (Greenfield) is pretty awesome, unless... there are legacy AP's and Clients within range, then an N-Only configuration goes into Protection Mode - which means every frame transmitted needs to do a CTS-to-Self, and this adds a lot of overhead to the channel... so to beat that, putting the WiFi chip into B/G/N mode invokes another form of protection called, appropriately enough, Mixed Mode which basically is legacy for management/control frames, and N for data frames...
so all good there...
20MHz vs. 40Mhz - some more overhead as the chipset needs to do a clear channel assessment for every frame on the secondary channel - this takes time which adds overhead and latency... so the cool kids just don't do 40Mhz channels...
FWIW - 40MHz channels - one loses 3dB on the Tx side due to the wider channels with most PA's, and this impacts both the AP and client side - so another reason to not to wide in 2.4, it cuts down the overall range, and impacts the link budget relative to narrow channels at any given range...
With TurboQAM (QAM256, e.g. up to 600MBit mode, whatever), this, on the Marvell (and other chipsets) invokes VHT mode - and this is non-standard for 2.4GHz - so we run into a lot of problems with legacy chipsets that run off the end of the pier with things they don't know, and with 11ac clients, they can get into a problem where they get a bit confused - they know they're in 11n mode, but the AP is sending control messages that they understand but should not do...
So that's the reason why folks that know the WRT1900ac family strongly suggest B/G/N-only mode for this device - it's the one that works best.
FattysGoneWild
Regular Contributor
Wonderful info! Thanks! I have made the change from N to B/G/N only mode. Wish I knew about this a long time ago. I have had this router now for a year and 6 months! Any other changes you suggest? Attaching a picture of current settings.
Bit off topic. I have a weird problem with the 5GHz band. It seems to have started when I added 2 6th gen (latest) iPod touches. My 5GHz will go down every 20-22 days. The light will be frozen and no response. You can bank on this happening every single time with in those days. It is the most bizarre thing I have seen with this router. I change channels. It will come back up maybe for a few mins or hours. Will do it again. Once I reboot though. I am good for another 20-22 days.
They are the only 2 AC capable devices I have online with this router using 5GHz. The rest use N with 5GHz. On the 2.4GHz side. I only have 2 devices. A HP printer and PS4. It might sound really stupid. But, I am at my wits end with this thing regarding the 5GHz going down. Wanting to just buy a new router. At the same time. I am thinking in the back of my head this is a firmware/driver issue with in it. It has not been updated since June. And I have read about instability on the 5GHz with this router. Dropping as I explained and random reboots.
I have performed factory reset, reflashed the firmware. Everything I know to do.
**EDIT**
Reading back more in this thread. Since I have always had 2.4GHz set to N. I bet that was the problem? As it needed to be set to b/g/n only mode from driver error stand point that Linksys needs to fix in their firmware?
Bit off topic. I have a weird problem with the 5GHz band. It seems to have started when I added 2 6th gen (latest) iPod touches. My 5GHz will go down every 20-22 days. The light will be frozen and no response. You can bank on this happening every single time with in those days. It is the most bizarre thing I have seen with this router. I change channels. It will come back up maybe for a few mins or hours. Will do it again. Once I reboot though. I am good for another 20-22 days.
They are the only 2 AC capable devices I have online with this router using 5GHz. The rest use N with 5GHz. On the 2.4GHz side. I only have 2 devices. A HP printer and PS4. It might sound really stupid. But, I am at my wits end with this thing regarding the 5GHz going down. Wanting to just buy a new router. At the same time. I am thinking in the back of my head this is a firmware/driver issue with in it. It has not been updated since June. And I have read about instability on the 5GHz with this router. Dropping as I explained and random reboots.
I have performed factory reset, reflashed the firmware. Everything I know to do.
**EDIT**
Reading back more in this thread. Since I have always had 2.4GHz set to N. I bet that was the problem? As it needed to be set to b/g/n only mode from driver error stand point that Linksys needs to fix in their firmware?
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FattysGoneWild
Regular Contributor
Well just an update. Since making that change. I have now gone past 20 days of up time. That has never EVER happened before with the latest firmware from Linksys. I always have had to reboot to bring the 5GHz backup every 20 days. I am now at 23 days and counting.
