Im planning on building my own router, as im gettimg a bit fed up to go through my third router, the first two tp links had their memory full and the wrt1200ac isnt supporting wpa3, which is important to me.
Im not quiet sure where to start, i know that its very likely based on the above mentioned s920. How much RAM and memory are recommended? Which Lan and wifi cards are working and recommended? For LAN 1Gbit is enough, as im not maxing it out in the near future. And for wifi, which one supports wpa3? Should i use the mpcie port or rather a usb dongle?
Can you elaborate on the type of router you are planning to build? Are you envisioning, for example, an x86 system (i.e. a small PC type device) or ARM based system? It would also be good to know what type of budget you have.
There are several ready-made router-type x86 and ARM devices (including the Raspbery Pi 4) that are really good for routing and relatively low power and cost effective.
I'd recommend external APs if you go with a Pi or x86 type system -- make those just simple wired routers and you'll get excellent performance.
Wired ethernet is 'easy', be it Realtek or Intel (other also tend to work, but those two are the most common options) - preferably PCIe based, but Realtek rtl8152/ rtl8153 also produces a decent USB ethernet card.
Wireless is better outsourced to dedicated APs, yes internal PCIe cards from Mediatek or QCA exist, but they (and pigtails && antennas) end up more expensive than decent APs - plus all the trouble with a single PCIe slot in most small computers (futro in particular) and proper antenna placement.
Also have a look at:
(in particular the later examples in that thread, avoiding AMD jaguar cores)
S920 + some nice mellanox /intel/broadcom 10gig card , 4-8gigs of ram and this works nice -with openwrt and pfsense/opnsense. I have had mediatek wifi 6 card with m.2 to minipcie adapter and had no problem with it. But personaly i'd go way of router + some nice ap for best coverage and performance. And the switch for cable devices is to determine what You want. I have tp-link 24gig plus 4x10gig as main switch in rack cabinet in basement, but upstairs i have zyxel 8x 1gig + 2x2.5 gig +2x10 gig and two is enough for my needs. And poe switch for ap's and cameras.
I wouldn't push my luck too much, power draw and heat dissipation are a concern with that kind of hardware, these are designed as thin clients with no (user servicable-) extension options in mind. While these 'might' work, they don't need to - nor would I expect the CPU to go all the way up to being able to route 10GBit/s (the PCIe connector only provides a single PCIe lane).
1x 2.5GBASE-T (a 2-port one if you're really trying to push it, but expect failure) or a 2-port 1000BASE-T PCIe ethernet card would be the most I'd be comfortable suggesting, we've already had reports that supplying a 4-port Intel 1000BASE-T card with power is beyond its abilities.
If you're looking for this functionality, better step one click up, to modern'ish SFF systems with 3-4 half-height PCIe slots and >=skylake i3/ i5 CPUs.
I would like to build a x86 system for around 100€. When i look at the responses so far, i think a single port 1 gig card (going to use a switch after that) and maybe that mediatek m.2 card with the adapter with external antenna routing, as i dont care about the looks as it should just work, do sound good. I also live in a very rural area and my internet is already bad enough, i dont expect getting fibre at best in 5 years or at the worst never.
Just about any all-in-one wifi router sold these days (and plenty of used ones) will cover this speed. you can get something for a fraction of the cost and a fraction of the energy consumption really easily.
Are there requirements that we're not aware of, or a specific reason you're looking to build your own?
To be fair, these speeds (even with sqm/cake in mind or other advanced features) are easily served by traditional 'plastic routers', mt7622bv+mt7915, filogic 8x0 and ipq807x can easily handle this (and would already be serious overkill already); specimens for either of these will be under the 100 EUR mark, including 802.11ax wireless.
I wanted to avoid the AIO-routers because of the reasons i mentioned above, the tp-links didnt have enough storage (the archer c6 was pretty much full after installing openwrt 22) and the wrt1200ac has wpa3 problems (because marvell apparently doesnt give out its driver code to foss devs that often or its bugged). I also like to DIY, i built my own PC, i modded my thinkpad X230 hardware and software (even installed coreboot) and i try to expand on that.
I forgot to mention that i want to use it as a OpenVPN Client, so AES-NI would be useful. And as a IPS/IDS system.
The wifi6/ 802.11ax capable cards capable of AP mode are the same as those in the plastic router mentioned above, with the same quirks and features (QCA ath11k (qcn9074) or Mediatek mt76 (mt7915, mt7916)).
The available flash sizes need to be checked individually, but in most cases you'll see 256 MB NAND or more (leaving you with at least 40 MB to your disposal).
RAM will start around 256 MB RAM, but most will offer between 512 MB and 1 GB.
If that's enough -or not- would be for you to decide - I am using an x86_64 router (and plastic routers as APs) with OpenWrt myself (albeit for much faster ftth speeds and sqm/cake; I have a 32 GB SSD, I need well under 50 MB (and that includes static SIP phone firmwares served via tftp from the router) - I have 4 GB RAM, actual RAM usage is around 100 MB), so consider me an x86_64 fan, but for those speeds it really is overkill.