My laptop has a 500GB SSD and I couldn't spare two fifths of it for the blockchain so I plugged in a portable 2.5" HDD, altered the command appropriately and it said:
The blockchain is on a rotating drive: this will be very slow, use an SSD if possible
..but I did it anyhow, it took originally perhaps five days for the whole blockchain. Then after a pause of perhaps three months, it has again taken about two or three days just catch that up.
What exactly is it doing? Clearly not just downloading something and putting it on the drive. My internet connection here is quite fast. The speed at which data is written even onto a rotating HDD is likely orders of magnitude greater than the internet connection.
Can anyone write a high level description of what it is doing whereby the slower read write speed somehow compounds to make it hugely slower.
Well, I haven't tried it yet with a plug in SSD so can't be a hundred percent sure that that is the bottleneck but it seems so. I have never before in my life had anything not work adequately due to hard drive speed. RAM, processors, video cards yes, they have limited things, but this is the first time a drive has limited something.
It seems that transacting in Monero requires specific equipment.