@twaldher1: That is not a valid test.
When throttling upstream to max, in my case 12mbps, latency on the connection jumps to 200+ms and I see downstream performance issues.
This is completely normal. When saturating your upstream link, ICMP (along with most other traffic, for that matter) will be buffered behind pending packet sends. This will cause a dramatic increase in latency.
The latency issue with the Puma 6 chipset is completely different, and fairly well documented for the lay-person here: https://www.theregister.co.uk/2016/12/03/intel_puma_chipset_firmware_fix/
To avoid the type of congestion you're seeing I would recommend you use a router with a decent QoS setup, and make sure it's configured to throttle at the router at around 90% of your true upstream capacity (95-99% for downstream). This will leave adequate headroom to prevent the type of latency spikes you're seeing. I personally use an Asus RT-AC88U with the AsusMerlin firmware and do not experience any latency issues when running a speedtest at 220Mbps down/11Mbps up. For reference, I'm on an SB6190 with the "v" revision firmware.
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