I got a SB6141 about a month ago and have been experiencing problems with it. The issues don't seem like what has been described elsewhere, so I was hoping for some feedback.
Typically, I will get 30 Mbps down, and 6 Mbps with about 14 ms ping time to my closest server on speedtest.comcast.net. After some period of time (which can range from minutes to days -- but usually in the 2-3 day range), the speeds will start degrading. Degraded download speed can range from 300 kbps to 15 mbps down, and upload speeds of 3.5-5 mbps up and is very erratic. Ping times are unaffected.
Once the speeds degrade they never go back to normal unless you power cycle the modem or log into the modem and restart it. Restarting/power cycling the modem seems to fix the problem about 1/2 to 2/3rds of the time. If it doesn't fix it, rebooting a second time doesn't seem to have much impact.
Downstream SNR is about 36/37dB, power level is -4 to -7 dBmV.
Upstream power is 37-39 dBmV.
Model Name: SB6141
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.10-SCM00-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.18m3
Hardware Version: 7.0
Serial Number: 348781223525072508010001
Firmware Build Time: Oct 29 2012 18:07:13
Comcast's Tech Support has been unhelpful. The best I got was someone grudgingly admitting that numerous users had reported issues with the 6141 and suggested I get help here and/or to get a SB6121 which he said worked better.