Performance issue: How to speed up the site in edit mode?

One of my client site is running extremely slow in the edit mode. While viewing the site normally, it runs fine but once I login to make changes, the site gets too slow and it takes a few attempts to modify a page.

I usually get "Maximum execution time of 30 seconds exceeded". The other C5 sites running in the same web server are running fine in edit mode. That's why I don't think increasing the execution time in php.ini is the best solution. It could be something in the website that's causing it. The C5 version is 5.5.1 with only 2 addons being used.

Even when I try to "Clear Cache" or change "Cache & Speed Settings", I get max execution error or I get a blank screen. My current Cache and Speed Settings are as follows:
Basic Cache - On
Full Page Caching - Off
Full Page Cache Rebuild - Automatic
I am unable to make changes to these as well.

I tried a local copy of the site and this is working fine.

Not sure what's causing the slow speed. Is there a way to detect this? Any solution that you can recommend?

View Replies:
jordanlev replied on at Permalink Reply
Try the MISER plugin:

I've had good luck with it on slow sites. Free for non-commercial sites, small fee for commercial sites (contact the author there for info about purchasing).
BlueFractals replied on at Permalink Reply
If all else fails, I might have to look into this plugin.

For now I just wanted to figure out why the same website is functioning well in my localhost and not in live site. Like I mentioned in my original post, there are other C5 sites running in the same remote server and they are functioning perfectly. Is there a way to do performance tests to find out what is causing the delay?
adamjohnson replied on at Permalink Reply
What about disabling the Concrete5 cache locally and then uploading that back onto your remote server? Lot's of folks have actually reported getting faster speeds with the Concrete5 cache disabled.

On top of that, the latest version of Concrete5 is, so you may have luck upgrading the the most recent version. Here's some instructions to help with that:

Do your error logs tell you anything? Any 404 errors on your site? It might make it easier to troubleshoot if we had the URL.