caveats for synchronous hardware based replication?

Hello,
Thinking about synchronous hardware based mirroring using EMCs clariion
product line over a dedicated fiber connection between two geographically
separate data centers. I realize that there is a basic speed of light issue
here regarding the distance I can have between the two sites and still keep
my servers synched real-time.

Would someone please shed some more light on what is involved here? What's
the maximum distance I can have betwen these sites and why? Any other
caveats with this setup I should be aware of? Thanks.

BTW - running an OLTP environment SQL2000.
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