Consultancy required for Drupa7 - SOLR search optimization

Dear All
My environment details are as below.

OS - Cent OS 6.3
Drupal - 7.15
Apache SOLR - 3.6.2

It is a job site, and users keep adding their resumes and day by day the
resume counts keep incrementing. I have around 3000 users now in my site.

When users upload the resume, I create a node and add the resume as
attachment. With this in next cron run, the node is indexed as well as
document. I am able to search the document. So far so good.

What I have observed recently, my search time is more. If I am searching
with 4 or 5 key words, it is taking around 7 seconds to show the search
result (I have only 3000 odd nodes in system with word document
attachment). SOLR taking 7 seconds to search 3000 documents , does not
sound good.

I strongly believe I am doing something wrong. I need somebody
help/assistance in this regard. I am ready to pay the consulting fee as
well.  Can somebody help me to reduce the search time.

Best Regards
Kamal
Bangalore, India