I was on Blast, which was 150 mbps but then jumped to 200mbps. It was in a package with cable. I had called to cancel cable, with the intent to cancel the wifi in a few more weeks, after US Internet could hook us up with fiber optic. US Internet offers 300mbps for $50 and the Xfinity rep said that they had a deal for 650mbps for $60, so I dropped cable and upgraded with that 650mbps internet from Xfinity. You can jump to the "That brings us to today..." paragraph, but the paragraph's in between contain the details of what I have already done to try to figure this out.
I had been using a Netgear CM400 modem that works great. When the speed was supposed to be 150, I would get 165-185. When it increased to 200, I would get between 217-242. The morning after the account switch, my 5ghz was 157mbps and my 2.4 band was cut in half. I don't want to distract by talking 2.4, routers or wifi. I am talking ethernet wired download speeds. Over about 48 hours, I spent about 6 hours with 4 different tech support reps. I also bought two different full gig+, DOCSIS 3.1 modems; Netgear CM1100 and Arris SB8200. I switched around ethernet cables (all CAT 5E OR 6). All connections were checked and this house was wired for cable for the first time by Xfinity just 6 years ago, which means that their cables would be the same today. I tested speeds with 3 different types of devices that I wired to the modem while testing on each. After about 36 hours, my speeds started to climb, as if somebody flipped a switch, but those speeds were (are) all over the place. When using app based testing (Ookla, etc.), they fluctuate between 90mbps and 500+mbps. Most frequently landing closer to 350. When I do browser based testing, it is far more consistent, between 125 and 145mbps. That is using fast.com and xfinity's browser based test page.
That brings me to today, when they had a technician come out. He had some sort of dedicated "speed testing" device that tested the speed while directly wired to my Arris SB8200 modem. He got 700+mbps speeds, through several tests. But using every other type of device, wired or over wifi (including his own phone) it was the same type of results as I had before; ~140mbps browser based testing and all over the place results using any of multiple testing apps. He even went as low as 40mbps once on his phone, through the Ookla app. The last possible thing that we could do was remove anything that was mine from the mix. So we brought in their new combo box for their ultra high speed customers. All their coax (all previously installed) and their ethernet cables. When he tested it with this that same "speed test" device, he was in the 700+ range again, even eclipsing 800mbps on one test. Yet, when we wired anything else to the the Xfinity modem or used wifi (again, including on his phone), we were right back with the same testing results that we had through my equipment.
So the issue does not seem to be equipment based. The only thing that I can think is that they are somehow handling these high speed packages differently than everything else and these devices for testing are calibrated to understand it, but nothing else is running it correctly. I have used so many devices and equipment from so many major manufacturers (Samsung, LG, HP, Netgear:older and newer models, Arris & TP-Link) that if that vague guess were correct, I would have expected forums to be booming with similar complaints (which they aren't). I have even concidered esoteric anomalies like weird magnetic zones, except that I am not new to the house nor Xfinity's wifi service. The tech left after 2. 5 hours just as dumbfounded and I said that I would hold on to their equipment and see if something magically happens over the next 48 hours. If not, I am hooking up my equipment again and returning theirs.
I know that this has been an overwhelming amount of info, but I would like to figure this out before I go back to the fiber optic choice**. Because this is so bizarre, I really don't want to have the intensive instalation of fiber optic internet if there is some issue so inconceivable, that 4 phone techs, one other visiting tech and myself, all haven't figured out. If something could produce the same results no matter what I choose at these higher speeds, then if fiber optics high speed of 300mbps would effectively be half speed results, then I would rather deal with my current issue of half speed results of 600mbps. Any insight would be greatly appreciated.
**= I had Fios fiber optic cable/internet for years in California, so I don't need the whole "bro, go fiber optic if you can, man." I completely understand the benefits. But it would be a lot of time and effort being put forth, if I am potentially going to be in a similar situation with their high speed.
