Hi zzzzz,
It is hard to make a choice in CMS as any answer you get is always going to be weighted in bias towards that persons particular preference. I do not believe that XOOPS is the fastest CMS out there, but in saying that I beleive the difference between the top 10 (of which XOOPS is one of) is only really good for bragging rights. There is going to be nothing substaintial enough performance wise that should be of any serious consideration in your selection process.
The basic fundamentals as the others have mentioned above are what do come into play here, and your selection of CMS is not the only area that dictacts this. After all, you don't bake a cake with only one ingredient do you.
From top (being CMS) to bottom (being hardware), these are some things you'll need to look at when determining performance of your site.
CMS
- Cache. Setting up your cache correctly in your CMS can make a massive difference in performance.
- Modules. Some modules are hugely more resource hungry than others. A part of any evaluation should include thorough testing of any modules you intend to use.
- Theme. The amount of http requests, and content weight (particulary graphics) that are generated by your theme also play a large part in site perfromance. Obviously the lower the better performance wise.
- Content. One thing people tend to do is display a great deal of non essential content on their front page. Minimise this, and you'll also minimise page weight. Another thing is to limit links/content to external sites such as banner ads, images, news feeds and the like.
- MySQL connection. You can use either a persistent or non persistent MySQL connection. Which option suits you best will depend on your hosting environment.
PHP - On a busy site PHP optmisation can have a big effect. Running PHP in something like FastCGI mode (available for IIS and Apache) and using caching such as Turck MMCache and Zend Optimiser are highly advisable.
MySQL - I haven't tinkered with MySQL optmisation a great deal, but there is always
chapter 7 of the MySQL manual for guidance here
.
Web Server
- Performance here ties in closely with your PHP settings i.e FastCGI. Other things you can do is use http compression such as (among others) gzip (apache), ZipEnable (IIS 6) and HTTP Zip (IIS 5 & IIS 6).
Hardware
- What hardware you use is dependent on all of the above as well as site traffic. Ultimately it is your CPU, Memory and HDD's that are going to dictate performance here, and your server is only going to perform as fast as the weakest link in the chain. For example, if you have a very busy site and have a 3Ghz processor with 2GB of PC-3200 RAM, but only have a single ATA-66 5400RPM IDE hard drive, then anything that isn't cached is going to have very poor performance.