[Koha] Server hardware questions

[Mirko]

We will get a new server for our Koha-installation. I was wondering,
how important some things might be. I don't want to know what is
essential to run Koha but what would be beneficial if available and
what does not matter at all.

Our installation now feels really slow and I hope to change that
before we go live with all features. We will have around 40.000
biblios in the DB.

I was thinking of a multicore CPU (probably quadcore) so we can run
Zebra updates, local scripts and other things frequently and not
interrupt regular use of OPAC and staff client. Does that make sense?

Does Koha work well on 64bit Debian? Are the Debian packages
available for 64bit?

Does it make sense to have more than 2 or 3GB of RAM for Koha
performance? In that case we would need a 64bit system. I'm under
the impression that a lot of the "database stuff" happens in RAM, is
that right?

Would the use of an SSD instead of a regular hard disk be favourable
(if the price does not matter)? Does it affect Koha performance?

Are there other things worth considering regaring server hardware?

Thank you in advance,

Mirko