You can speed up the bitcoin core sync time by downloading the whole blockchain in a bootstrap.dat file, then letting your bitcoin wallet work on that. It still takes a long time to sync but it's faster than waiting for the data from nodes. You can download the bootstrap.dat file from this link.
http://www.satoshis.guru/blockchain-downloads/I would urge anyone thinking about doing this to think twice. The bootstrap.dat linked from the website could actually be some kind of attack, although I don't know exactly how the file gets used so I can't tell you what the vector might be.
Anyway, since 0.10, the bootstrap.dat method is basically obsolete. It is not faster than downloading directly over the Bitcoin network, so it serves no purpose.
It's probably too old bootstrap.dat file. 27 GB only???