All,

I'm posting this for two reasons:

- So someone else in the same situation can (hopefully) find this thread and figure out what is going on

- To request Netgear to update their settings due to climate change ;-)

I've spent the past few weeks frustrated and running around in circles, as my 400+MBPS ISP connection would connect (on the LAN side) at 1GBPS, but drop in a few minutes to 100MBPS. The ISP (Comcast) reprovisioned the modem multiple times and ran tests on their end to no avail. I changed the ethernet cable between modem and wifi router, even changed the router itself, but the problem wouldn't go away.

I'll save you my long story of misery, but last night, I finally found the root cause while going through the Event Log of the CM1150V (Adavnced --> Administration --> Event Log).

Here is what it said:

Critical (3) THERMAL THROTTLE: Temperature 75C, transition to state Elevated 1

Now, I don't know about y'all, but where I live (Texas), we've had some high temperature days this season (>100 F/38 C).

I tested by placing two giant fans near the cable modem and blasting away. Here is what it said after a few minutes:

Critical (3) THERMAL THROTTLE: Temperature 73C, transition to state Normal

I've retested it, and these events perfectly correspond to the ETHERNET link dropping from 1 GBPS to 100MBPS (or vice-versa). The Ethernet port light also switches from Green to Amber, and the other way around. (This was the clue which led me to this discovery eventually).

So, here is my request to Netgear:

- Is there a way to add a heat sink or some other solution to the modem for indoor applications in hot climates like the Southern US?.

- Can you please update the throttle setting to a higher temperature in the next FW update, or make it configurable? At the very least, give the customer a way to disable the throttle (show them all the legal disclaimers, and void their warranty if needed).

Thanks,

Frozen in Texas with my AC set to 76 F / 25 C

Forum Discussion

CM1150V - LAN speed drops from 1000 to 100 MBPS - Thermal Throttle past 75C