Is SEO or Joomla crashing my server?

[carteluo]

Hello there.

I have a dedicated server (cPanel) with this 1.5 joomla site with high traffic (10.000+ visits per day). It's a regional newspaper, which is edited everyday with 200 articles. This articles expired at 3am and then they are put into archive. These articles are then accessed through a separate php system with a wrapper but that is another story...

We decided to enable the option of SEO to short the links, and it was working very well but the spell lasted just two weeks. The server start to overload very very high, like 150 to 200 of load, making it inaccessible in any way. When I could access it, disable the joomla seo, and the load lowered.

I thought "hey maybe is the joomla default SEO that is not strong to handle that kind of work" and then I installed AceSEF... Incredibly after two weeks, again the very same problem.

What do you think? Maybe I should upgrade Joomla? But what if after upgrade this problem still happens?

Thank you in advanced,
Luis.

[joomlovenow]

what's your webserver ? has the traffic increased after seo-urls ? how many sites are on your server?

[joomwork]

Do you have any active cron jobs?

[carteluo]

Do you have any active cron jobs?

Yes, I have 3, but they run at a specific time: 3:00am, 3:05am and 4:30am.

[carteluo]

what's your webserver ? has the traffic increased after seo-urls ? how many sites are on your server?

Intel Core 2 Quad CPU Q6600 @ 2.40GHz
4GB Memory.

No, the traffic remained the same. There are 15 sites.

EDIT:

Forgot to say:
Joomla 1.5.23
PHP 5.3.10
MySQL 5.1.61

Thank you.

[irandream]

What extensions do you use?

Could you check the amounts of SQL queries that your site creates? ( Global configure > Debug site.)