On Dec 19, 2007 6:04 AM, Stuart Bishop <stuart@stuartbishop.net> wrote:
> Hi.
>
> We are looking at upgrading our primary servers. The final boxes will have
> 128GB ram, fast disk arrays and 4 CPUs.
>
> We currently have some eval units with 8GB ram and crappy disk to let us
> benchmark CPU choice. One box has 4 3GHz dual core Opterons with 1MB cache,
> the other box ha 4 3GHz quad core Xeons with 4MB cache.
Imagine two scenarios. In one you have an infinite number of hard
drives with an infinite amount of battery backed cache, and an
infinite I/O bandwidth. In the other you have one disk. Which one is
likely to be I/O bound?
Yep. So, it's not likely you'll be able to do a realistic benchmark
of the CPUs with such a limited disk subsystem...
> For pgbench (PG 8.2 running Ubuntu), the Opteron is getting about 6x TPS
> over the Xeon (3000+ TPS on Opteron vs ~500 on Xeon). Things get a little
> better for Xeon with PG 8.3 (570-540 TPS).
pgbench is a mostly I/O bound benchmark. What are your -c, -t and -s
settings btw?
It's would be much better if you could benchmark something like the
real load you'll be running in the future. Are you looking at
reporting, transactions, content management, etc...?
