[CentOS] Software RAID resync

I have configured 2x 500G sata HDD as Software RAID1 with three partitions md0,md1 and md2 with md2 as 400+ gigs

Now it is almost 36 hours the status is

cat /proc/mdstat Personalities : [raid1] md0 : active raid1 hdb1[1] hda1[0] 104320 blocks [2/2] [UU] resync=DELAYED

md1 : active raid1 hdb2[1] hda2[0] 4096448 blocks [2/2] [UU] resync=DELAYED

md2 : active raid1 hdb3[1] hda3[0] 484182912 blocks [2/2] [UU] [==========>..........] resync = 51.8% (251168768/484182912) finish=1975. 7min speed=1964K/sec

unused devices: <none>

I have reniced the md2-resync to -10

Q1. Does is take this long? Q2. How to speed it up

Regards and Thanks

Rajagopal