[Linux-ia64] 2.4.9 vs 2.4.18 for HPC

With respect to Itanium2 what advantages does 2.4.18 have over 2.4.9 in
an HPC environment?

My concern is that RH7.2 does not have a 2.4.18/19 kernel and probably
will not.  For support reasons, running 2.4.9-34 from RH may be
required.  I am curious about the possible performance and stability
issues with 2.4.9 on Itanium2.

I am trying to build a case for software development on 2.4.18/19
kernel.org kernels.

Thanks.