Anna Jonna Armannsdottir wrote:
On mán, 2008-07-14 at 13:01 +0200, Angelo Hongens wrote:
All the servers I usually buy have either one or two quad core cpu's,
so it's more the question: will 8 cores perform better than 4?
If not, I would be wiser to buy a single Xeon X5460 or so, instead of
2 lower clocked cpu's, right?
In that case we are fine tuning the CPU power and if there are 8 cores
in a Squid server, I would think that at least half of them would
produce idle heat: An extra load for the cooling system. As You point
out, the CPU speed is probably important for the part of Squid that does
not use threading or separate process.
But the real bottlenecks are in the I/O, both RAM and DISK. So if I was
buying HW now, I would mostly be looking at I/O speed and very little at
CPU speed. SCSI disks with large buffers are preferable, and if SCSI is
not a viable choice, use the fastest SATA disks you can find - Western
Digital Raptor used to be the fastest SATA disk, dot't know what is the
fastest SATA disk now.
This whole issue comes up every few weeks.
The last consensus reached was dual-core on a squid dedicated machine.
One for squid, one for everything else. With a few GB of RAM and fast
SATA drives. aufs for Linux. diskd for BSD variants. With many spindles
preferred over large disk space (2x 100GB instead of 1x 200GB).
The old rule-of-thumb memory usage mentioned earlier (10MB/GB +
something for 64-buts) still holds true. The more available the larger
the in-memory cache can be, and that is still where squid gets its best
cache speeds on general web traffic.
Exact tunings are budget dependent.
Amos
--
Please use Squid 2.7.STABLE3 or 3.0.STABLE7
