Drupal 7 Really Slow on admin pages

Question

I have a Drupal 7 installation and several admin pages are incredibly slow and time out after 30 seconds. I've tried several things without success:

• APC is enabled
• innodb_buffer_pool_size is set to 100 M
• No unused modules are enabled. I still have 155 modules enabled, for localization, commerce, captcha, questions & answers, etc.
• Standard cache is enabled and JS/CSS compression enabled. Memcached not being used.
• Drupal 7, latest version

Even with that, the site is still really slow and there are pages that won't open (time out). For example, installing a module will always fail the first time. Accessing the settings of the Language Selection Page module will always fail, and so on. Any recommendations other than increasing the timeout?

I'm using WAMP.

UPDATE: The time out error shows it takes a while in this function mainly: drupal_flush_all_caches( ) ..\system.admin.inc:1766

Sometimes in other functions too.

Answer 1

If you can profile your site that's always helpful. https://drupal.stackexchange.com/questions/724/why-is-drupal-7-so-slow

https://groups.drupal.org/node/210683 - Older post but some patches have still not been committed.
https://groups.drupal.org/node/415883 - Speedups for the DB layer (caches mainly).

Because of windows checkout this post and this group
https://groups.drupal.org/node/242443
https://groups.drupal.org/drupal-windows

Answer 2

After researching a bit more, I think I was able to improve its performance a little bit.

I've changed several variables in MySQL. Some are not recommended really (the first one mainly), but as I'm in development it helps:

• Set innodb_flush_log_at_trx_commit = 0 (Source)
• Increased query_cache_size and query_cache_limit
• Increased innodb_buffer_pool_size
• Changed semaphore table to memory by executing this script

Also,

• Disabled the Update manager module (not sure if it helped)
• Uninstalled the Content Translation (and dependent modules) as I was using Entity translation