Is there any reason for putting it on a second circuit?

The only real advantage of a new ring is that you could wire it with high
integrity earthing, which is now required for rings expected to have large
amounts of Class I equipment likely to cause earth currents. You would
attach this to the non-RCD side of any consumer unit, although possibly with
its own RCBO if earth leakage current detection is required.

To wire a high integrity earthing circuit, you need sockets designed for it
(with 2 earth terminals). It is much easier to wire a high integrity circuit
as a ring, as the earthing must take two independent routes. With radials
and spurs, this is difficult and basically requires you to continue the ring
anyway with just the earth, so there is no advantage to a radial circuit at
all.

If large amounts of computer equipment are attached to a ring, it can push
the quiescent leakage up quite high, making the RCD too sensitive to any
other equipment and liable to trip, especially if the RCD is shared with
other circuits.

I wouldn't bother with a separate circuit myself. I would put the rings onto
RCBOs, rather than a shared RCD, though, so that all the quiescent currents
on all the circuits don't push the shared RCD into an oversensitive zone and
to give good discrimination between circuits.

Christian.