Re: problems with postgresql speed

On Monday, December 3, 2001, at 04:30 AM, Ludva Radomír (KM) wrote:
>
> Two machines:
> 1. Pentium3 400Mhz, hdd 8Gb, 64Mb RAM, kernel 2.2.14-5.0 (RedHat 6.2)
> 2. Celeron 400Mhz, hdd 8Gb, 64Mb RAM, kernel 2.2.14-5.0 (RedHat 6.2)
>
> The same database, the same postgres Version 7.1.3, the same
> configuration.
> Only processor is diferent, ...
>
> Queryes from client application on Windows over ODBC:
> 1. 40sec.
> 2. 90sec.

This may be due to the difference between the cache sizes of the two
processors. IIRC, the celeron has only 128k of cache while the P3 has
512k. Even though the P3 cache runs slower (I think the celeron runs
at full clock while the P3 runs at 1/2 clock), the larger size may
prevent
a lot more cache misses which makes it much faster.

Databases are extremely I/O bound, so anything you can
stuff into cache is probably worth it.

--Jeremy