Disk Utility - Format Time for 500GB (Zero Out Data)

Hello.
Is there one length of time for formatting a hard drive with one pass of Zero Out Data? For instance, does the length of time change depending if you format with zeros using USB2, FW400, FW800, or eSATA?
*My Format Setup*
LaCie Rugged 500GB All-Terrain (USB2 & FW400/800)
FW800 Cable
GUID Partition Table
Mac OS Extended (Journaled)
Zero Out Data (One Pass)
I'm formatting with a FW800 connection. Disk Utility has said it will take 1.5 hours for about 3.5 hours now. The blue bar has progressed even though the time remaining is incorrect. At this rate, it will take seven hours to format 500GB.
I'm going to be formatting multiple 500GB and 1TB drives, and I'm wondering if the time I'm experiencing is normal. Therefore, it should take a day to format 1TB with one pass of zeros. Is this correct?
Thank you for your help! =)
Message was edited by: Revearti

It takes a long time to zero out data on a 500GB drive. The larger the drive, the longer it takes. I don't think the connection makes a difference, since each of your listed options are high speed. Never tried it on an external with USB 1.1, so can't give you any real time experience there. But it will take well over an hour to write zeros on every block of a 500GB drive.

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