Extremely slow speed on my site using codeignitor... is this normal?

[eluser]alitech[/eluser]
I am not a techie and went with what was recommended to me by the people who initially built my site. They recommended codeignitor as it was a fast way to produce sites. I didnt really know much about this and went ahead with the recommendation. Now almost a year on, the site has been extremely slow as it has grown in site. It has about 150,000 page on it now and it is growing consistantly by about 200 pages per day. I plan to do product imports on the site which will push the number of total pages to over 10 million. This is going to be a complete nightmare as the server is constantly overloaded and the site responds extremely slow.

I have been kicked out by 3 service providers because of the load on the server the site causes. I am not on a dedicated maching with a quad core 2.8 GHZ proc, 8GB ram and 1TB hard disk. This has not helped either as the server goes down constantly because of the load. I have been monitoring Apache and the maximum traffic I can achieve is about 180 threads at the same time.

I am told that with codeignitor on every page load, the index page is referenced/loaded as well? Is that right?

Anyways, I know this is a public forum and I hate putting my URL out on support forums as its bad press, but I am at my wits end with this stuff. Please have a look at http://www.123vouchercodes.co.uk

I have had the code optimised a few times and there is still some more to be done, I will get that done as we go along. Any suggestions on what I can do here?


I am also attaching a screengrab of my google webmaster account for site performance. Its appalling as you can see.