I thought that this was the old days when it took forever for bitcoin core to acquire the bootstrap but it looks like it's still the case. I basically ran the program for 2 hours and I'm still under 10h. Any idea on how to fix the problem or download the blk files elsewhere ? Why can't I find the equivalent of the bootstrap as a torrent ?
I don't think you have a problem, but are seeing expected behavior.
Bitcoin Core is downloading and verifying about 80 GiB of data. Even with all the improvements that have been added, this will take several hours to days depending on your hardware.
Bitcoin Core is a full node. It mirrors all the information of the blockchain, and checks it first hand. By running Bitcoin Core, you become part of the users that verify and provide the network's data for others.
You could take a shortcut and acquire an already verified set of data, but then you'd be trusting a third party that they didn't add incorrect information to trick others in the network. However, that's exactly the point of why you'd run a full node in the first place: When you do, you can be certain that you have a correct copy of the blockchain.
If you don't require full node security or feel that it is too much hassle to synchronize with the network, you might find it more comfortable to run a user oriented wallet. You can find a comparison at Choose your wallet.
The bottleneck when synching up w/ Bitcoin Core is likely to be hard drive access and I/O time.
I have a 5 year old (full size) HP pavilion dv6 laptop running Windows 7... CPU usage rarely exceeds 20%, so changing the task priority does nothing to speed up the process.
With a 56 Mbps connection there can be many minutes when the network usage is only a percent or two, followed by periods where it's 10-50% or more; after sucking down the data it then has to crunch it all. So connection speed likely won't make a big difference.
Go into Task Manager (ctrl-alt-delete) and under the Performance tab there's a button for the Resource Monitor, which has a tab for the Disk; this will show processes with disk activity, and you can see there how bitcoin-qt.exe is keeping the disk activity pegged near the max (10 Mb/s for me) most of the time. Task Manager also has a Networking tab where you can follow what's happening there.
I still have 31 weeks to go and it's now taking ~1 hour per week of progress, or a little more. Back when I was still 1½-2 years behind it was 10-15 minutes per week of progress; at ~3-4 years behind I first began to notice it taking several minutes to click down another week.
Current total blockchain size is 86 Gb, and it's adding ~1 Gb per week of progress, so I'm guessing it'll total out at ~120 Gb.
This is definitely an issue for BitCoin if the thing pyramids in size to where nobody new can synch up with it.
I first started ~7 weeks ago and have been working on it ~3 hours a day maybe 3-5 days a week; with all the disk usage my machine is not very usable when it's doing this.
Hope this helps someone.
You can download a compressed bootstrap.dat to reduce the first time block synchronization. i.e. https://flo.sh/bitcoin-qt-bootstrap-dat/
Using a bootstrap.dat file may also be useful if you need to setup multiple nodes and want to avoid every node loading the complete blockchain itself.