About twaldher

For what it's worth, the firmware fix never fixed mine.  The issue was less pronounced but remained. There are grumblings that the Puma 7 chipset has the same issue, unfortunately that's the chipset in Comcast's latest lease XB6 modem.  I recommend just buying an Intel version like the SB8200 and if you want to lease wait until Comcast has an Intel version.   On the SB8200, if I saturate my upstream, latency goes from 15ms to 50ms.    ... View more

@neatchee wrote: @twaldher1: That is not a valid test.   @twaldher1 wrote: 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. No, not normal. Laptop, direct in to my SB6190 - bad latency when upstream is saturated. When I had a tech here, we swapped out my Arris modem for another brand he had for testing on the truck, direct to laptop again - no upstream latency issues when saturating the upstream side. Now, if I saturate my download side, yes, latency goes up, but it only goes from 11ms up to 40ms, with occasional single ping spikes to 100ms.  Never 200ms. ... View more