X86: WiFi speeds slow and can't create 2.4GHz and 5GHz at the same time


I am a total newbie, struggling with slow download speeds over WiFi. My ISP gives me 250MBit/s download speeds, but I only get max. 90MBit/s on 2.4GHz (often as slow as 30MBit/s) and 105MBit/s on 5GHz. An ethernet cable gives me full 250MBit/s.

Additionally, my issue is that I can either create a WiFi network on 2.4GHz or 5GHz, but not both at the same time. See LuCI:

If I click on "Add", I can create another WiFi point and choose a different frequency, but then the first one gets changed to that same frequency too.

OpenWRT is running on Fujitsu Futro S920 (x86) with the Atheros AR9382 802.11ABG/N Mini PCIe WiFi module. I have installed ath9k and luci-app-sqm. I experience the same issues when sqm isn't running.

Here are some details:


Do you have any idea how to increase the WiFi speed AND enable 2.4GHz and 5GHz simultaneously?

Thanks a lot! Sorry for being a newbie boomer... :older_man:

you can't.
one card= 5ghz or 2.4ghz. multiple essid yes, but on one band and same channel

use 5ghz band and set 40 Mhz, that shoud give you max speed from that card.

I don't know much about networking yet. But don't commercial routers provide both frequencies (2.4GHz and 5GHz)? Why is OpenWRT on x86 different?

in your pc you have just one card, abgn, dual band. most router have two cards one for 2.4 and one for 5 ghz. this is a pc not a router, right?

Well that's a bummer. I didn't consider that when I was getting this Fujitsu with all its parts. Yes, it's a pc, not a router.

What can I do? Some of my older tech doesn't support 5GHz WiFi and to be honest, I don't even want to put up with 100Mbit/s when I am paying for 250Mbit/s from my ISP, so even 5GHz on Fujitsu would currently be a bad choice.

Would you recommend a commercial router as an access point?

well i do not have experience with openwrt on pc, you can buy an ap or if you can, replace the wifi chip, look for mt7915 DBDC. this is a dualband wifi 6 card.

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Okay, that's a good tip, but this module doesn't seem to be available where I live (Germany). Besides, I am now starting to doubt that simply being able to switch between 2.4GHz and 5GHz would solve my issues since the 5GHz speeds are also rather unsatisfactory...

So I gather that an access point would probably be the best option which should (hopefully!) give me full speeds. But I can already hear my wife's voice: "Are you crazy? Why did you replace the small neat and well-functioning router for THREE power-hungry devices?" I've got some explaining to do...

Any recommendations as to a good and power-efficient access point? Or rather sell the Fujitsu, buy a router and flash OpenWrt on it?

Well, AR9382 is still just 802.11n - which isn't that fast by modern standards (at all), 802.11ac and 802.11ax brought real improvements in this regard (but they both run hot and need a lot of power, probably too much for your Futro).

https://www.mediamarkt.de/de/product/_d-link-ax1800-mesh-wi-fi-6-range-2723624.html (just guessing your potential location) might be the cheapest way out (not a top-end device, but cheap and mt7621a+mt7915DBDC - which gets on sale really cheap from time to time, like right now).

Disclaimer: I have no personal experience with mt7621a+mt7915 so far.

x86 makes a great routing platform (although possibly overkill and likely with higher power consumption when comparing against all-in-one wifi router). But x86 is generally a terrible wifi device insofar as the limited performance and functions of the wifi hardware (USB and PCI cards).

An all-in-one wifi router or a proper AP will usually run circles around x86 for actual wifi performance.

If this is your full internet speed, most wifi routers made in the past 5 years (maybe more) can handle this throughput without breaking a sweat. The equation is different if you'll be running VPNs (especially if you use an older/bloated VPN protocol like OpenVPN).

In your case you're using this as a router, so there's still value in your setup, but I'd recommend that you look at purpose built APs or wifi routers.

BTW, see this thread where the OP was trying to make a dumb AP out of an x86 system....

Fujitsu's Futro Thin client range is a bit special in this regard, the Futro S740 can go by with 3.4 watts (semi-)idle (measured at the mains plug), the Futro S920 goldmund is using is specified for 4.5 watts idle (and that's reasonable) - you just don't have that many extension options (and WLAN in particular, only one slot with limited power supply).

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Well, that's pretty cool about the crazy low power consumption! So as a router, that device is probably quite a great option. But, as has been established, not so much for wifi.

If you plan to keep the Fujitsu Futro S920, you could open it up, remove the atheros mini PCIe wifi module and simply replace it with another wifi 5 (802.11ac) or wifi 6 (802.11ax) capable device. While doing so, take care to choose similar form factor.

mt7915 as PCIe seems to be rare in german market.
mt7921, you could go for, if you feel adventurous. Since it is a very new device drivers have to mature still.

Found some mt7921 on german amazon:

Or here:

Keep in mind, if you want to run your device in accesspoint / repeater / bridge / monitoring mode, then best wifi 6 Linux supported cards are from Mediatek and Qualcomm. AFAIK Intel (which offers many cheap M.2 cards), only supports Linux with wifi drivers that are capable to be run as "client". Have a look at Suggestions on x86's mini pcie / m.2 wifi card: both in AC & AX for ap mode to find PCIe devices that are access point capable.

Thank you all for your replies, I am quite blown away by the number of responses which have been very helpful!

I think I would like to try to keep the Fujitsu Futro, I love the fact that it's so power-efficient. I also want to run Wireguard and Adblock on my router and I am not sure how a conventional router copes with this load, so x86 seems like a good choice. If WiFi speeds could be improved by getting another WiFi module, then that would be the best option.

Do you mean this stuff? I am a little confused, because the current WiFi module is plugged into the Mini PCIe slot in the CENTER of the Futro and I don't think that the mt7921 would fit. The PCIe slot is occupied by a PCIe Ethernet card. So I am not sure that this setup would work... Or have I missed something?

You may be able to get some reasonable modules, but typically a dedicated AP device is the best bet in terms of performance (including multiple radios capable of MIMO or even MU-MIMO, better antenna designs, etc). Even modest APs can typically do better than USB or PCI modules.

Okay, would you be able to recommend a dedicated AP device? I know that the D-Link AX1800 Range Extender has been previously suggested (thanks, slh!), but I would prefer something that can either stand freely or be mounted to the wall. Support for 6GHz would also be great. I'd be okay with paying a little more for more functionality and, most importantly, high energy efficiency.

Yes, kinda :smiley:
If you need Mini PCIe then a mt7921 mini PCIe card might be a better fit. Looking at the datasheet i thought there was a free PCIe slot, but apparently I was wrong.

Psherman might be right though. Connecting via rj45 adapter to a dedicated AP device could be more efficient, if you want to max out wifi performance. To illustrate this argument:

  • Going the mini PCIe route, you would need to choose compatible antennas too.
  • Going the dedicated AP device route: Manufacturers will have made a decision for you already and it is likely that they probably have been doing some tests to confirm compatibility with the antennas they deliver to you.
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was sold on amazon.de for ~70 EUR until very recently

is also a convincing device, but a tad more expensive

if you can't get either, this might still be an option (but the dynalink is much better)

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Thank you! Yes, that makes sense. I'll keep the Futro and get an access point. Do I understand it correctly that I should flash OpenWRT on the AP too? Or does the original firmware on the AP remain?

EDIT: Thank you, slh! Great suggestions, I'll look at them!

All of the suggestions I've made are fully supported by OpenWrt, that's the type of configuration I would be suggesting. Some AP-only devices might do well with their respective OEM firmwares, but I'm not following devices like that.

The DAP-X1860 might not have overwhelmingly long range, it's not the fastest ('only' 2x2 802.11ax, only 2*880 MHz mips 1004Kc), but it's very cheap (right now) - and beats any USB card by a huge margin, as well as most cards you could put into the futro.

EDIT: the three options above (dl-wrx36, rt3200/e8450, ax3600) are also top candidates for router usage, as well as AP usage, the DAP-X1860 is only (really-) useful as AP (with a wired backhaul) or extender/ repeater (wireless backhaul).

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Thank you all so much for your advice and suggestions! I am really amazed and thankful that you have taken so much time to answer and even do research for me.

Much appreciated!