WD Passport 1TB USB 3 - Very slow for USB 3... even after Format!

I think there might exist bad sectors (I have run HD tune and it shows some in the beginning, I didn’t let it run full scan, because it takes ages to complete…), but most probably from software fault, not because of faulty disk surface (which, of course, cannot be fixed). Maybe a utility such as HDD regenerate 2011 could give the solution, but it costs 54 Euros! Is there any free utility to do the job? Can simply CHKDSK do the same?