Ssd is needed (or enough ram) due to random access of state. See my reddit post from a year ago, full sync took 25 hours: https://www.reddit.com/r/ethereum/comments/7n4v64/correcting...

There's a lot of misinformation, some originating due to genuine problems (trying to use a hdd or geth with barely working garbage collector) and misunderstandings, some from intentional lies (especially two r/bitcoin moderators - thieflar and stopanddecrypt).