running internet cable
i have 40 gb + 6 gb hard disk

i have redhat 9 + squid 2.5 stable 1 ( upgraded version) on 6 gb harddisk
wana interest 40 gb for squid cache

so i need some help

idea is better to divide the 40 gb into two 20 ,20 gb partitions then two entries of ' cache_dir ' of these two partitions in the squid.conf
or create only the one partition mean only one cache_dir in squid.conf

second question is
which version of squid is best in case of squid 2.5
stable 1 is best or install the latest version which is stable 12
i have found that on fedora core 2 and 3 that stable 3 and stable 5 are not as speedy as stable 1 on redhat 9 ,so can some one suggest me which is better for cache hitting