Joined: 02 Oct 2016 Posts: 7 Location: Liverpool, UK
Posted: Sun Oct 02, 2016 13:04 Post subject: Asus AC66U - DD-WRT Bug (In a large % of v3 Betas)
So it took me some time to work this out but for some reason all the v3xxx betas have a problem with this router in respect to maximizing bandwidth throughput.
I've tried several from the May releases (maybe more) of the last updates in sequence as they have come out over the last several months, and they all have the same issue. There is about a 50 to 65% reduction in download speed.
I was getting anywhere up to 55mbps on v3 including the latest 30709 build. I actually thought it was my ISP throttling, but after upgrading from 152Mbps to 200Mbps today and getting a new modem, I see it wasn't as the same problem was being exhibited (I also only really today decided to do anything about it)
Downgraded this to the last BrainSlayer release DD-WRT v24-sp2 (12/22/14) giga - build 25697 and I'm now getting 130mbps upwards all day long and that is in peak hours, so i expect a margin of reduction
Last edited by dodgyscouser on Sun Oct 02, 2016 15:06; edited 3 times in total
Joined: 02 Oct 2016 Posts: 7 Location: Liverpool, UK
Posted: Sun Oct 02, 2016 14:41 Post subject:
Per Yngve Berg wrote:
The Single core 600 Mhz MIPS processor is not capable of driving a 200 Mbit/s Internet connection.
Get a Dual Core Router, i.e Netgear R7000
Is the speed test from a wired or wifi client?
Have you set it to max clock speed 662 Mhz
Yes....it is capable, i think i've just proved that going from 55mbps to 130mbps using the older non-beta firmware.
The is definitively a clear and very visible reproducible problem with the later firmware not the router.
Load wise however, i was at anything from 50-70% on builds v3xxx and now I'm only 6%-20% on BrainSlayers and not even breaking a sweat at 140mbps.
So you see I'm not complaining at the 130mbps, its the 55mbps I'm pointing out, because its the DD-WRT firmware thats causing it, nothing else. The restriction now is because its a Sunday afternoon and my provider has certain throttling in place.
Wired Cat6 through a Procurve 2810-48G.
600Mhz. Yes
Last edited by dodgyscouser on Sun Oct 02, 2016 15:21; edited 3 times in total
If it's a K3 kernel, it wasn't labelled as so when referred to on the interface so I just assumed a v2 v3 release mechanism based on the filename. I've only ever until recently (Jan/Feb this year) used those builds.
It also only changed to show v3 when I updated it, but then I'm probably not as close to the releases as others to understand the kernel versions.
Joined: 02 Oct 2016 Posts: 7 Location: Liverpool, UK
Posted: Sun Oct 02, 2016 15:12 Post subject:
Per Yngve Berg wrote:
Same Build Number.
You can see the Kernel Version in Status->Router
30709: Kernel Version Linux 3.10.103 #14357 Thu Sep 29 13:44:40 CEST 2016 mips
K2.6 have been reported to be faster on old routers, but I do not know that there should be a speed difference here.
Got you. I was in a bit of a rush earlier when I first posted, so didn't have a lot of time to do some further digging.
"Firmware Version DD-WRT v24-sp2 (12/22/14) giga - build 25697. Kernel Version Linux 3.10.63 #5241 Mon Dec 22 05:39:52 CET 2014 mips"
It seems an odd one to be honest over why I should see what feels like a cap on the 3xxx build versions.
Joined: 02 Oct 2016 Posts: 7 Location: Liverpool, UK
Posted: Sat Apr 22, 2017 8:21 Post subject: Update
So before I decided to go forward with getting a Netgear X8 R8500 I decided to take a look to see if there have been any fixes or improvements in the firmware, because if I'm honest I really don't want to have to blow the best part of £300 if i can.
I'm sorry to say it hasn't been fixed, not is it any better.
If I switch back to the R25697 (22/12/2014) build my wired throughput is upwards of 150Mbps.
Clock is at 632Mhz and 40% load.
Still clearly an issue with DDWRT.
Disappointing really.
EDIT: So here is weird, I read something in the forum on one of Kongs builds for a different router and someone was seeing a reduction of speed when the PPTP (VPN) server was enabled.
I've just disabled it on mine and the speed has gone from ~44Mbps up to ~97Mpbs. I know this isn't the expected 150Mpbs+ but it is an interesting change. Repeatable too if you enable/disable at will.
The R7000, R7800, and R8500 will easily handle your 200Mb bandwidth. The lesser R7000 is good for around 400Mb. No matter how you try to spin it your router is too under powered. _________________ Segment 1 XR700 10Gb LAN, 1Gb WAN ISP BS
Wired AP 1 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 2 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 3 Unifi Wifi 6 LR US 1Gb LAN
Syslog Services Asustor 7110T NAS 10GB
NetGear XS716T 10GB Switch
download1.dd-wrt.com/dd-wrtv2/downloads/betas/ (Brain Slayer)
YAMon https://usage-monitoring.com/index.php
Joined: 02 Oct 2016 Posts: 7 Location: Liverpool, UK
Posted: Sat Apr 22, 2017 13:28 Post subject:
I disagree IMHO, proved only by the load on the CPU when being stressed. I am looking at replacing the router anyway, but it's not the point.
That said, the focus should not be on whether or not it's a 200Mbps capable router but rather the drastic difference in throughput between builds.
The absolute and undeniable fact is that later versions of DD-WRT on the AC66 have issues with handling the ~150Mbps throughput, it's a software limitation, not hardware If it was underpowered, you would see the same limitation on ANY release.
If I use the earlier build I can get ~120Mbps to 150mbps throughput all day long, if so in this instances something must have changed (driver revision lib file etc)
OK yeah fair enough it's not 200Mbps, but no-one is every going to get full flat out bandwidth ever for various reasons, it's just the nature of networking and as I said earlier, this isn't the issue.
I'm struggling what is so hard to understand, you should never see a 100Mbps drop after coding/updates. It is the entire point of a software development lifecycle and testing to drive these things out.
On the same hardware:
Early r25697 build ~120-150Mbps /w VPN
Later r31825 build ~40Mbps /w VPN
Later r31825 build ~95Mbps /wo VPN
I've also come across another problem with the build and Plex and UPNP, when I go back to the earlier revision it configures UPNP in the router with no problem for remote access.
Just refuses to do it on r31825, even won't allow the connection (dropped) with manual port forwarding.
I disagree IMHO, proved only by the load on the CPU when being stressed. I am looking at replacing the router anyway, but it's not the point.
That said, the focus should not be on whether or not it's a 200Mbps capable router but rather the drastic difference in throughput between builds.
The absolute and undeniable fact is that later versions of DD-WRT on the AC66 have issues with handling the ~150Mbps throughput, it's a software limitation, not hardware If it was underpowered, you would see the same limitation on ANY release.
If I use the earlier build I can get ~120Mbps to 150mbps throughput all day long, if so in this instances something must have changed (driver revision lib file etc)
OK yeah fair enough it's not 200Mbps, but no-one is every going to get full flat out bandwidth ever for various reasons, it's just the nature of networking and as I said earlier, this isn't the issue.
I'm struggling what is so hard to understand, you should never see a 100Mbps drop after coding/updates. It is the entire point of a software development lifecycle and testing to drive these things out.
On the same hardware:
Early r25697 build ~120-150Mbps /w VPN
Later r31825 build ~40Mbps /w VPN
Later r31825 build ~95Mbps /wo VPN
I've also come across another problem with the build and Plex and UPNP, when I go back to the earlier revision it configures UPNP in the router with no problem for remote access.
Just refuses to do it on r31825, even won't allow the connection (dropped) with manual port forwarding.
This is no bug, but a fix which unfortunately lowers throughput, if you want more throughput run command:
