So i don't tend to download very large files often, mainly just the few PC games i've purchased over the years (titanfall, SC2, BF 4) i noticed this problem with those...but even more so when i was downloading GTA V last night. my modem when downloading these large files re boots quite a bit on its own. i thought it was kind of weird with those other games...maybe just kind of freaky incidents with TWC repairing something or whatever. but after it did it a handful of times last night with GTA V i decided to google search the problem and it looks like it happens quite a bit to others as well. it only happens when downloading large files. day to day use is just fine. i'm not sure if theres something i can do on my end or if i just need to contact TWC and request a tech come out. anyone have this problem before?
I would request a tech to come out and take a look. If it's only happening with large files, maybe the modem is just not able to handle it which shouldn't be the case. Also, do you own your own modem or is it a leased modem from TWC? I've found it's better to own your own because it make sense financially but you can also pick out your own modem. A popular Docsis 3.0 modem that works really well with cable is Motorola SB6141, or you can opt for the slightly cheaper SB6121.
I second the docsis 3.0 suggestion. Also, if you go that route, make sure TWC removes the monthly charge from your bill.