At the urging of Comcast, I have replaced my venerable Motorola SB6121 Cable Modem,( as Comcast said it would no longer be supported and would limit my internet speed,) with a Comcast approved Netgear CM500. Prior to the change, in spite of the fact that we have Blast! service (currently described in my area as 100mbps) I have been pegging consistently at +/- 25 mbps. Comcast blames the modem, although it was an 8 channel download and 4 upload docsis 3.0 device rated at 343 mbps. I switched over to the Netgear modem with no issues. The new device is working perfectly well, but at that same 25 mbps. Again I spoke with a rep on the phone, she tried restarting, reprovisioning, had me check cables etc, basically blamed my wiring, or the new modem, and said I should rent a Comcast provided modem. I have been down this road before and was worn down and gave up a couple of years ago. Now I'm starting to get seriously frustrated that I have purchased a new "supported" Modem and am continuing to not recieve the speed that I am paying for. Is there any way that I can definitively confirm at my end if this is throttling due to the profile of my account or some Hardware or wiring issue?