We are facing issues with our server as its constantly going down with the CPU usage going to 100% often and site pages loading very slowly.
We need an expert to fully optimise our cs-cart store, server and database for faster loading.
What are your access log summaries showing? How many active users when your site goes out to lunch? Generally this is caused by robots beating on your site to the point when your server can't handle the load.
Optimization of the cart won't help with that scenario. However, if the number of active clients is reasonable then some degree of optimization should help. But if it's caused by robots attempting to deny service, then that needs to be addressed at your hosting (or .htaccess) level.
Click the link in my profile and I'll take a look for you when you provide access info.