Whenever you have sata cables on drives lag like that.
Its a sure fire way of saying the cable is going soon and to grab another one.
I wouldn't say it's for sure a cable... lots of bad sectors or a dying HDD can do that, and is usually more likely to be the cause as well.
Yes I already pulled it out from the enclosure however the machine lagged when I inserted one of the drives using a sata cable. I used the optical drive cable because I didn't have any spares.
Try booting off of a Linux LiveCD such as Ubuntu with the drive(s) directly connected via SATA. Windows absolutely hates bad sectors and lags like crazy when a drive that has a lot is connected. Linux can usually get around them a little easier. You just won't be able to copy any of the files that are located on bad sectors - you can still copy around them though.
If there's any important data on the drive(s), back it up, and then try running a chkdsk, either from Within Windows (if you can), or via the Windows pre-boot recovery menu.
Via the command prompt, do: chkdsk X: /f /r
where X: is the drive letter