Raid 5 adding another drive, takes FOREVER?!

[idata]

I started out with a RAID 5 consisting of 3 2tb drives, and I have added a 4th. Intel Rapid Storage Techonolgy v9.5.0.1037 has ben running the migration for about 5 days now, and it is at 43.7% complete. I was away for the long holiday weekend, and when I left it was at around 32%, so it's basicaly made a little over 10% progress in 72 hours. At that rate, it will take another two weeks! The origional raid was around 2/3 full. Is this expected behavior? Or am I getting what I deserve for asking a software raid to do big boy raid tasks?

By the way, system info:

North bridge - Intel x58

South bridge - Intel ICH10R

Proc - Intel i7 980X

Drives - mix of WD, Hitachi, and Samsung

OS - Win7 x64

Intel RST v9.5.0.1037

[idata]

So 23 days later... and the sofware has finished. After a reboot to get windows to recognize the added space, as the instructions say is necessary, the new drive is EMPTY!!! (with just some windows files like $RECYCLE.BIN) Words can not express my disapointment in Intel. What the # $&% is wrong with this stuff? Is there any chance I can perform something to get data back?