bitcoind sync is utilising very little CPU and bandwidth and is very slow
Make sure you are connected to enough peers (maybe >4)
Make sure you use either the default -par config value or you set it according to your available CPU cores (usually num of cores +1)
Make sure, you have fast disk access (ideally SSD). If disk access is slow (don't use NFS, NAS, etc.), it could tear down the verification process (leaving your CPU partially unused)
Try to change the default database cache size. A -dbcache of 4GB can really significant speedup the sync, though don't over-allocate if your system has not plenty of RAM to waste.