Are there actually many truly stable SOCs left?

Hey guys,

I'm a big fan of OpenWRT, and for ages my "go to" device has been the Archer C7, which has a single core 720-775Mhz MIPS QCA95xx SOC (slightly different SOCs for different versions). But it is getting long in the tooth, and it seems like newer builds have issues with 2.4Ghz WiFi:

I run a small IT support business in the UK - and most people here can only get a 80Mbps download, 20Mbps upload VDSL2 connection maximum through an Openreach based provider (Openreach runs the old national telecoms infrastructure and FTTP rollout is a complete mess and way behind where it should be). There is Virgin Media for DOCSIS asymmetric 10:1 ratioed cable (100/10, 200/20, 350/35, 500/50) - but their network is unreliable and they are overpriced - and they don't care as they basically have no competition purely on speed and know it. There are a few independent FTTP providers (Hyperoptic, Gigaclear etc.) but they barely have any coverage (mostly newly built flats - Hyperoptic actually use ethernet runs inside blocks of flats run from an ONT on the side of the building I believe).

Anyway, I digress.

I frequently look at the "What's your favourite cheap LEDE/OpenWrt device?" and "What's your favourite enthusiast LEDE/OpenWrt device?" for ideas to replace the venerable Archer C7, and it seems to boil down to these SOCs (with my notes):

  • MT7621 - can be found in the Edgerouter-X, Mikrotik Hex (RB750GR3) (no WiFi on these) as well as some cheap imports that also have WiFi. They tick the "cheap" or "cheapish" box at about £50. But... it just looks like they aren't stable at all:

I don't want to use EdgeOS on the ER-X - I tried V1 and didn't like it anywhere near as much as OpenWRT, and I also managed to brick a device through the simple act of flashing a firmware update from the web GUI (it ran out of space as it keeps two firmwares on the device at once, supposedly for a "recovery" boot - in fact I ended up having to take off the cover and restore EdgeOS using a serial USB adapter). And if you look at the Ubiquiti forums, it looks like EdgeOS V2 is a hot mess...

  • IPQ40xx - the two main devices that seem to come up are the Fritz!Box 4040 and the Gl.iNet GL-B1300 (Convexa-B). These still seem to be available in the UK (about £80ish). However, there have been issues with VLANs:

Also, the GL-B1300 stock firmware is based on 15.05 Chaos Calmer with backports:

They say they are stuck there due to QSDK. I can't seem to find any verifiable reports on this forum about the WiFi performance of the B1300 on newer vanilla 19.07.x builds.

(There is also the EA6350v3, which for a time was only £30 in the UK. But it is now really hard to get hold of for less than £50, and apparently there is also a v4 that doesn't use the IPQ40xx SOC, so it's not a "dead cert" buy).

  • Marvell mvebu a53 - these are in the Linksys WRT1200/1900/3200/32X routers, but apparently WiFi is not a hot point. They are also quite expensive and hard to find in the UK. One device that caught my eye is the Gl.iNet Brume, which has a 1Ghz clocked version (no WiFi). But it's £120...

  • Raspberry Pi 4 - a bit of an outlier... Once you factor in a PSU, case, MicroSD card (or SSD as it now boots via USB) and a USB3 ethernet adapter (unless you do router on a stick, but then you have to have a managed switch too) you are at over £100. I don't like the idea of running an edge device directly off of a MicroSD card either. It all just seems a bit fiddly and not the solution.

  • X86-64 - I myself run a clown car setup - I have an Asus Chromebox with a Celeron 2955u, 16GB mSATA drive and 4GB RAM. It's massive overkill - I only have 200/20 cable (from Virgin), but I retired my Archer C7, which I was using with SQM on just egress, in favour of the Chromebox (which I used to use as an HTPC with Kodi before I got my Fire Stick 4K). I run the Chromebox as router on a stick - and I use a BT Home Hub 5 flashed with OpenWRT as a managed switch to trunk everything (cable modem, LAN, Unifi AP) on one cable connected to the Chromebox's single Realtek NIC. I really only tried this setup as a test - I expected it to just fall over and not provide a stable connection (so many "wrong" elements - the Realtek NIC, single port, weak old router as the managed switch). But it actually works great - I can easily shape both ingress and egress with cake and piece of cake and it doesn't break a sweat. And it hasn't locked up or crashed or had any issues at all after about 4 months.

However, I still wouldn't be confident to deploy my hacked together setup for clients - too much to go wrong. In terms of other X86 hardware - sure, there are plenty of cheap old SFFs on eBay I could buy and whack a decent Intel NIC in - but this would be large and loud and a hard sell for most residential IT clients. Most of them are used to a tiny plastic box, not a honking great one as big as their main PC!

I found @jeff's excellent post comparing throughput of various SOCs really helpful:

But also a little confusing - it seems like there is little difference between ath79, ipq40xx and mt7621 when it comes to SQM as it seems to be purely single threaded?

For most clients I actually only use a router without WiFi enabled and then either setup multiple Unifi or TP-Link Omada APs if they have a way to run a wired backhaul, or a consumer mesh system like TP-Link Deco, BT Whole Home or Eero if they don't. The router is mainly a way to break away from the terrible free routers most ISPs in the UK give to customers - OpenWRT allows me to set a custom DNS easily, as well as configure SQM with cake and piece of cake - the main reason I deploy OpenWRT is really for SQM to make the most of the limited speed offered by Openreach.

So I guess where I'm at is - I'm still tempted to use an Archer C7 (or other ath79 device), even brand new. Sure, the single core MIPS is weak and old, but the key thing for me is stability (especially for wired only deployments where WiFi is handled by APs or mesh). Sure, mt7621 and ipq40xx SOCs are newer and more powerful, but what's the point of putting them in for clients if the router keeps rebooting or the WiFi is poor (when needed)?

If the Marvell stuff (especially the Brume) drops in price, I guess that could be an option. But a brand new Archer C7 (which will likely be a V5) is only about £50-60 in the UK, will happily shape an 80/20 VDSL2 connection without WiFi enabled, and will run stable.

For a brief moment Eero caught my eye as they implement SQM in their firmware. However, two big issues are:

A) they don't support PPPoE in router mode, which is what Openreach use. That means you either have to use them purely in "AP Mode" (therefore forgoing SQM) or put the main Eero in a DMZ. Neither works for me...

B) Amazon owns them and I'm not confident about the future of the product now.

So, what am I missing? Is there a device or SOC that can actually fulfil my needs other than the old ath79 target? That is stable, can shape 80/20 connections without issues and costs about £50-60 new?


The ip40xx issues are no problems, just decisions that devs want to use nested vlans instead of port isolation. :wink: Waiting for DSA, so I don't have to revert the ethernet driver changes to get port isolation working again.

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@PolynomialDivision that's good to know. Which specific device are you using? It does seem like the ipq40xx target is in the lead from the list above.

The only other issue for me specifically is UK availability; only Amazon sells the Fritz!Box 4040 - for about £80 but it comes with a 2-pin Schuko plug so there would be the need for a converter (yuk) or a UK PSU on top of that. For a time they had some in Amazon Warehouse deals for about £40 (also with 2-pin PSU), so adding a UK PSU on top still brings you home under £50. No stock anymore though. I guess they ship them from German warehouses as AVM are a German brand and way more popular over there...

The EA6350v3 was discussed above, so that really leaves the Gl.iNet GL-B1300, which is sold on Amazon with a UK PSU for about £80. That works for wired only but I'm still a bit concerned that once you flash vanilla OpenWRT you lose the Qualcomm drivers so performance might drop.

I keep hoping for a two gigabit ethernet port version of the Pi4. It would be perfect. I know there is the NanoPi R2S, but it doesn't look ready yet - still on snapshots and I'm seeing that it needs a mini (loudish) fan as it runs hot (but then so does the Pi4 under load...)

Also, a standard 5 port device like the Archer C7 means no need for a separate gigabit switch, which is a win for the Fritz!Box 4040 - the GL-B1300 has 3 ports.

The search continues...

Definitely Keep away from mt7621 and devices supported by mt76. Only issues and each fix contains new bugs.

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Well, I've just picked up an EA6350v3 on eBay for £35 posted so I'm going to have a play with that and see how it goes on my own 200/20 connection with cake/piece_of_cake SQM, VLANs and WiFi disabled (I have a separate Unifi AP) - but might also see how the WiFi is on it as well!

Let me know how it performs, I have that same router but want to switch ISPs. When I do that they'll give me faster downstream and I'm concerned it won't be able to handle that.

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Fritz!Box 4040/7530, Zyxel, ...
It is just a bit hacky to revert the changes, since the ethernet driver is often patched. :wink:

What? :open_mouth: I like mt7621, since it supports DSA and it is working very smooth. I can not confirm this. I'm very excited for mt7622(?).

It sounds like you are running snapshots right?

Hence the need to revert the ethernet driver patches on the ipq40xx devices?

I don't think DSA is in the stable 19.07.x builds for the MT7621 right?

I'd definitely want to stick to the stable builds since these will be for other people's networks (as opposed to my own where I can feasibly run the master branch and tinker away...)

This issue should be fixed in current master.

This commit?

As far as I can see not only is it stable it is more open and gets more fixes and features sooner e.g. AQL was lifted from it into the shared code for the ath10k devices.

I ran one of those and it was flawless. I think better than the archer c7 I'm using now.

I only stopped to give it away to my gf due to her wrt3200acm being buggy. It's been flawless for her household too.

There's enough posts in all the threads about mt7621 in my original post to make me cautious though... it sounds like there is a fundamental issue with switching that just doesn't seem to quite get fixed with every stable release - just as one thing seems resolved, another rears its head. Anyone else have solid uptime from an mt7621 device?

How is this for stability?: Optimized build for the D-Link DIR-860L

To be fair, I also have a second mt7621 device running in a different environment which would reboot/lock-up once a week on average. This is presumably because it is connected to a switch which utilizes pause frames, and for some reason there is a bug with the mt7530 that causes it to misbehave with pause frames. I have written an experimental patch that disables pause frames completely and this Monday it will officially have 4 weeks of total stability.

So depending on your environment, your mileage may vary :slight_smile:

Yes, to my understanding e73d866c6fc7dfad2fb7dd87345c90029bbda59d should fix the situation for both parties.

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For x86 you should be looking at de-commisioned Thin clients instead, usually fanless and have crappy specs for a PC but for OpenWrt it's plenty (512MB RAM or more is common, and plenty of internal flash space for OpenWrt). They are also more or less the same size of a router, or slightly bigger.

While older thin clients and Dell/Wyse clients are semi-custom affairs that need to be hacked to run something else that isn't their original firmware, HP thin clients from series 57xx onwards (and series 510 and 610 onwards, although the 510 use VIA CPUs and I hate VIA) are normal x86 PCs with a normal BIOS/UEFI and normal Sata/IDE interfaces, that can boot from USB as well.
You can find more info about thin clients on this site but also by just googling with the product name, many people are repurposing them as mini-PCs nowadays, and HP provides extensive documentation with service manuals and whatnot.

Decommissioned thin clients are (and will be) available in large numbers so in many cases you can also get discounts for bulk purchases.

Usually the ones with Atom CPUs (and later) should have a mini pcie slot you can put a card in to create a wifi network, or have already one with wifi n. These cards are easy to get and cheap, 10 euro tops.
Cables and antennas if needed another 5 euros tops. Not all thin clients have a hole for an external antenna, but it's usually easy enough to drill a hole in the back plate if they don't.

Since most don't have 2 ethernet ports, you can add a USB-ethernet adapter using the ASIX chipsets (realtek chipsets aren't great on PCIe but in USB adapters they really are unstable garbage).
For example the Ugreen brand ones you find on ebay are relatively cheap (10 euro for a USB 3.0 gigabit adapter) and use an ASIX usb ethernet chipset. I use them and they actually hold under 100% load for days on end when I'm running large backup jobs over the network. (Realtek ones... don't. Not even the realtek ethernet of my laptop is stable enough, it will reset or even lock up after a few minutes if actually loaded like that)

Optimal would be to get a thin client that has USB 3.0, but they work fine on a 2.0 port as well (will be limited to 100-ish Mbit speeds of course).

For example a good candidate with USB 3.0 ports and (empty) minipcie slot like a HP 610 can be found for around 50 euros (shipping included)
In the HP T610 I have, I had to drill a hole in the back plate to install an external wifi antenna, since it only has internal antennas though.

So yeah it's still a clown-car-ish setup, so you should probably keep this as a fallback in case you don't find routers that satisfy your requirements, but even if you are going for the best specs without no bulk discount like I did above you won't spend more than 100 euro or 90 pounds apiece for a complete system, and also since it is still overkill for routing job it will last a very long time.


About mt76: - just look how much open issues are there without responses, and how many commits are fixes for old mt76x2 and 7603 chipsets.
The same will eventually happen to mt7615 and finally to mt7915.

And about mt7621 - there is a patch for mt7530 which which fixes problem on some devices and introduces it on another.

@bobafetthotmail - thanks so much, that's a really comprehensive write-up. A lot of people on the Pfsense forums are really down on the use of USB>Ethernet adapters as if it's some kind of heresy, so it's good to hear the ASIX ones can take sustained load without falling over.

To be honest, even the single Realtek NIC on my Chromebox hasn't really had a hiccup either, but I see it as a bonus rather than the norm.

There are also ethernet cards available in mini-PCIe form factor, which is probably a better use for a single expansion port, than 'wasting' it on a single wireless card (this is cheaper/ easier to outsource to a simple OpenWrt AP).

How should I configure my ethernet with vlans?

I expect any thin client to come with one onboard ethernet card, if you have a mini-PCIe slot available, you can add another using this slot (yeah, you will have to do a little diy to fit the rj45 connector into the case). With two ethernet cards, WAN and LAN are covered, so you don't need to use VLANs for simple router uses, but you obviously can define as many VLANs as you like on the LAN (or WAN) interface and break them out to a managed switch.