Product associate and improve website loading speed in VM2

[a.abedi]

Hi
I'm trying to more than 1500 Books to almost 15 categories with multilingual web site (Persian and English) and would like to use the associate product function
I added them correctly and I made categories menu for both of them languages and associated to them on the web site as well.
Regarding associate each book on English to Persian and vice versa: Already on following link when I click on a selected book and then click on Persian flag I will be moved to the category of books Not to the selected book in Persian. 
http://www.*******.se/dena/en/world-literature/novel/6707-detail.html

And
How can I improve website loading speed? I thought that the Virtuemart can handle 3000 product on the database and 3000 books does not affect on the loading speed !!! 
Joomla! 2.5.14
PHP Version:5.3.16
VirtueMart : 2.0.22c
live site url: http://www.****.se/dena/
Joomla template: http://www.joomshaper.com/joomla-templates/istore

I appreciate any suggestions.

My

Thanks!!!

[Edit by Milbo: removed dangerous link]

[Maxim Pishnyak]

I'm trying to more than 1500 Books to almost 15 categories with multilingual web site (Persian and English) and would like to use the associate product function
I added them correctly and I made categories menu for both of them languages and associated to them on the web site as well.

Check threads which YOU already created. There could be replies.

[Maxim Pishnyak]

Don't load jquery from google in your VM settings.

Change your hosting service to another one. There are 33! web sites on the same server with your web site. It's not acceptable.

Your template loads 2nd copy of jquery.js. Get rid of this, please.

Speed of your web site shows your skill as web site creator.
1. What techniques did you use to speed up your web site?
2. What extensions from JED did you try to use to improve speed?
3. What threads from this forum section did you study to learn how to optimize performance?

[jjk]

I appreciate any suggestions.

While looking at your live site, it looked like a script on your live site was trying to install malware on my computer. Please check if your site has been hacked.

Before this malware killed my browser settings, I noticed that your site is loading two different versions of jQuery from googleapis. You need to stop at least one of them to make your shop work. Probably your template is also loading webfonts from Google, which often is very slow, too. Try to disable that if you can.

[RedJohn]

Don't load jquery from google in your VM settings.

Why you should not load jquery from google?
I thought that jquery from CDN accelerates page speed.

[Maxim Pishnyak]

CDN is good, but google is too slow in jquery case.