In a single domain structure we have 2 dc's the BDC more
powerful than the PDC, the PDC seems to be doing more of
the work, how can i better load balance these 2 server?

You can try changing the DNS weight value so your more powerful machine is
used more often for logons. Are both DC's in the same site? If so, a client
will use one DC at random so you should already have a crude load balancing
scenario in place. How do you know one machine is more often used than the
other?
This KB talks about the DNS weight. http://support.microsoft.com/?id=232025

"martyn" <(E-Mail Removed)> wrote in message
news:086001c3d5c6$48f4a7a0$(E-Mail Removed)...
> In a single domain structure we have 2 dc's the BDC more
> powerful than the PDC, the PDC seems to be doing more of
> the work, how can i better load balance these 2 server?
>
>