What do you mean, "to bring cable up to speed"? Commonly available DOSCIS 3 modems with 8 downstream channels can perform up to 300Mbps, and the manufacturer can add as many channels as needed.
That's not record-setting of course, but it more than covers the ISP speed offerings I'm aware of. Aside from fiber, which is not pre-laid for most last-mile applications, what would be faster?
I am pretty sure that is 300Mbps shared. And you rarely get that even in real world best case scenario. And much worst if you live in City and High Rise Buildings with High Density population.
DOCSIS 3.1 brings OFDM as well as up to 10 DL /1 UL Gbps. At that sort of speed, as well other added reliability features finally makes Cable a decent Alternative.
Speaking from experience in EU and Asia Area. No idea if it is the same in US.
In most parts of the US, it's cable we want an alternative to. We generally only have 2 options for internet service: cable, or DSL via the phone company (if you live in a large city and you're lucky, the phone company is Verizon and offers fiber instead of DSL). DOCSIS 3.0 is significantly faster than the DSL options generally are, so there's really only one choice if you want speeds greater than ~50 mbps. Here in northern Utah, my options are Centurylink, which offers ADSL with download speeds of up to 40 mbps, and Comcast, which offers DOCSIS 3.0 with speeds of up to 105 mbps.
If you have 40/20 (VDSL2, not ADSL) available from CenturyLink, you should be able to get 80/40 or 100/12 (don't ask me why) bonded. Pretty competitive with Comcast and more reliable in my experience. Their problem is that you have to be like 1500 ft. from their DSLAM for 40/20.
Cable is the only high-speed option in a lot of places in the USA. Most cable providers offer 20-30mbs where DSL options are stuck in the 3-5mb download and 512k-768k upload range. Those speeds make for very unenjoyable internet experiences.
I disagree with this. I think most people are not looking for a cable alternative, but an alternative to DSL. Fiber isn't really helping because it's rate limited by the ISP.
That's not record-setting of course, but it more than covers the ISP speed offerings I'm aware of. Aside from fiber, which is not pre-laid for most last-mile applications, what would be faster?