Fulltext optimization

[Mitja]

Hello,

First the specifications:
MySQL version 4.0.20
news database
670.000 records
1,5 GB data file
1,2 GB index file
indexes: id, date, text (fulltext)

The problem turns up when I want to search only between certain dates e.g.:

select *, (MATCH (text) AGAINST ('string' IN BOOLEAN MODE)) AS score from table where date>='date_from' and date<='date_to' and (MATCH (text) AGAINST ('string' IN BOOLEAN MODE))

The search without (date>='date_from' and date<='date_to') clauses takes only a few seconds. Search with date selection takes app. 30 seconds. I also want to be able to sort results by date desc and show only 20 results per page but this only increases query time. I already tried numerous ideas but non seemed to help. The machine is 2,4 GHz P4, with 1 GB RAM and SCSI disks. I really don't have any other idea so any thought is very welcome.

Thank you in advance.

Mitja