Subject Re: [firebird-support] dimensioning server RAM
Author Alexandre Benson Smith
At 17:16 27/01/2004 +0000, you wrote:

>according to which rules of thumb does one establish the right RAM
>qty of a FB server ?
>In my case, I need to run about 10 similar databases, each of which
>runs SPs that are both computation-heavy and disk-RW-heavy SPs.
>Peppe Polpo

Hi Peppe,

There is no rule of thumb for server configuration/sizing...

A bunch of things should be known...

1.) Wich OS (Linux have SS and CS, Windows SS only I don't know if CS
version is ok for production)
2.) How Many users
3.) Classic or Super Server
4.) What is computation intensive
5.) What is disk-RW-heavy
6.) What the performance expected
7.) What the size of the DB
8.) The system will be a OLTP or DataWareHouse (does anyone still uses this
term ?)
9.) Could you spare the databases across multiple servers ?
10.) and a lot more that I don't think right know...


The bottleneck generally are Disk I/O and network bandwidth.

Having RAID disks with good controller(s) is a good starting point
Having an applications that reduces the bandwidth use is good too...

I have read some messages that if you can afford a lot of RAM CS will be
better, and runs better than SS and can take some advantage on SMP
machines. I don't use CS just SS, and don't have any SMP machine... so
can't say much on this...

If you cannot afford a lot of RAM SS is the right choice (since cache is
I think if you have a lot of RAM FB 1.5 will be happy in using it to sort

AFAIK if you set page buffers too high the speed will decrease... (more
than 10000 pages if I remember right). I think you will need to test...
Incresase the page buffers do some tests, change the value of page buffers,
max sort memory, etc, rinse and repeat the tests... I think this is the
only way you could know what is better for you.

If the computation is heavy a good processor will help.

HTH [for not giving any direct answer :(]

Alexandre Benson Smith
THOR Software e Comercial Ltda.
Santo Andre - Sao Paulo - Brazil


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