Hi,
I activated 1Gps internet and I can only get around 500Mbps download speed. I think the bottleneck is the router. When I run a test with speedtest.net, this is what sysstat shows:
All CPU cores get 100% utilization on softirq, probably handling net_rx ones. Wan dev utilization is only 50% as expected. RX drops goes pretty high, probably because of the CPU saturation.
I have already played with the eth dev features with ethtool but no improvement.
My next option is playing round with the kernel tuneables with sysctl for the TCP stack, but I was wondering if there are some specific things I should look at, or just buy a more powerful router.
out of curiosity ... if you want to give it a try,
19.07.10 has swconfig driven network
maybe you could try to downgrade and make speed test
this way it will be clear, it is pure CPU problem, or if it is DSA, then there are a hope that one day things maybe sorted out
bcm53xx has only been migrated to the DSA based b53 switch driver in late October (master), 21.02.x is still using swconfig (and will continue for its remaining release cycle).
I have a switch in my office that connects to the router, which is that lan4 you see. My internet test go from the switch to the router to the internet. The speed between computers connected to the switch reaches close to 1Gbps.
Your router has a dual core Armv7 (A9) running at 1 GHz.
I do not think it is capable of doing LAN<>WAN at 1 GB/s.
Broadcom has proprietary hardware offloading called CTF (Cut Through Forwarding) which will get you 1 GB/s (note this is incompatible with SQM) but I doubt that is available on OpenWRT.
There are a few, I do not know them all so just my personal take:
Netgear R7800:
But only if you use the NSS builds which are not regular builds.
More modern and very powerful:
Something which maybe is not permitted to share in this forum but other third party firmwares might use the Broadcom CTF module so as a stop gap you can try those.
I administer some Broadcom Netgear R6400 and R7000 which are using another third party firmware (because they are not well supported on OpenWRT due to the Broadcom closed source code) and those can do around 900 Mb/s LAN<>WAN with CTF&FA enabled.
However I cannot guarantee that works for your R8000 with its tri band configuration it is something of an odd duck.
The r7800 is certainly a top device, but it's no longer in production and 'only' 802.11ac (and modern 802.11ax successors can be even cheaper than their 802.11ac predecessors). Without NSS, ipq8065 is good for (plain-) routing up to 500-550 MBit/s (which will reduce a tad with DSA in the medium term future), less with PPPoE, SQM or VPN on top. Personally I would not suggest buying any device with NSS (which is very, very unlikely to 'ever' be merged into OpenWrt/main) in mind, if you already own it and can extend its lifetime that way, fine - but just don't rely on its presence as a buying decision.
Simple 1 GBit/s routing (at wirespeed) should be possible with mt7622bv+mt7915 or filogic 830 based devices (sadly not quite with ipq807x, for the same NSS rooted reasons, otherwise these would be great alternatives as well), but if you want more of a margin, you end up at.
OpenWrt on x86_64 and a simple (OpenWrt supported-) 802.11ax AP makes sense these days, see e.g. these for low-cost entry-level devices
Other options (beyond mt7622bv+mt7916 or filogic 830) include
RaspberryPi 4, with a second rtl815x based USB3 ethernet card, sadly still scarce and way overpriced
NanoPi r4s and similar (supported-) rockchip based devices
various 4-port x86_64 mini-PCs (starting new around 180 EUR)
BananaPi BPi3/ BPi4 are a bit more diy devices, but also quite promising.