ddrescue is taking ages

ddrescue is taking ages

OK, so my hard disk crashed the other day and I sent the entire notebook
for servicing; now I have a brand new hard disk installed in it and the
damaged one out in the open. I've installed Ubuntu and ddrescue with the
intention of recovering all data from the C drive (200GB); so far it's
been about 2 hours and I think it's going to be a very long time.
I ran the following line:
sudo dd_rescue /dev/sdb2 /mnt/sda4/backup.img
Things started looking good; it expected to retrieve 195354624kB from
/dev/sdb2 and started copying stuff; however it's copying in chunks of
2119808kB with avg.rate of just above 400kB/s and an ETA of almost
130:00:00. I have to wait 5 days just to get all my data out?!
This webpage says that he took just 12+h to do 1TB, but given that my hard
disk is damaged I should expect the time taken to be longer. Should I be
optimistic and pray that it'd take less than 5 days? Currently the state
of the hard disk is so bad that I can't view any of the files in Windows,
the C drive says it's corrupted and unreadable, and the D drive hangs up
the system when navigating through the files, and eventually disconnects
each and every single time.
Is there any way to expedite ddrescue (while preserving as much data as
possible), or am I doing something wrong?