"The hardware requirements are not as large as you
would think. The most important aspect to consider is the RAM that
is available for Squid. RAM is important because each object in the
cache requires a small amount of memory. Generally, 32 MB of RAM
are required for every GB of disk space. If you run out of memory
there will be a significant reduction in speed.
"The other major consideration for Squid is disks. The faster
the disk read and write the faster Squid will operate. Usually it
is a good idea to consider SCSI for disks on a proxy server just
because of speed. The other advantage that SCSI has is that it can
access 7 different drives allowing for multiple reads and writes
without a slowdown in access."