I've seen well-connected machines in data centers sync it in as little as five hours. @Kannan is on the right track. I hope this post will be a little more prescriptive.
Disk, Network, and CPU performance matters. More precisely, it's "latency" that makes the big difference. Latency is the lag between request and response.
- Network: No wireless because that adds latency. Plug into the best wired connection you can find.
- Disk: SSD, of course. They are ideal for random nibbles all over the place. If you have battery-backed write cache that is ideal. It's one of the reasons the server-class systems can do it faster.
- CPU: A VM will do it. I get by with 2-4 i7 cores.
- RAM: An Ubuntu VM with 4GB of RAM will be happy running
--cache 2048 which will speed things up.
--light mode. Depending on whether you're running
geth from command-line or from a wallet GUI "out of the box", the mode will either be the default or something you selected. If you're looking for a way to speed things up with a slower hardware system, you may have to select a mode other than the default. Investigate the options. Do you know what mode it's using now?
- Don't interrupt it. Matters have improved so it's not the complete setback that it once was but, generally there is a lot going on in the RAM that hasn't been fully worked out and committed to disk. Interrupting the process increases the overall time needed to finish the job.
There's no reason a reasonably decent laptop won't catch up eventually. If conditions are less than ideal (it's always less than ideal), just expect it to