This article is devoted to increasing site performance for registered users. There are two ways for to this: use Block Cache module and use Drupal caching. Below is the detailed description of the first one.

So, if you need to increase performance of your Drupal-based site you should cache blocks. You can do this with

• Block Cache module – blocks caching or
• Drupal caching – create your own cache functions

Block Cache module

You can download this module here: Block Cache.

The module is implementation of blocks caching. It caches separately from the main сache, has its own table and works stable. The most essential difference from the main cache is that Block Cache will work even after you enter site as a registered user. It saves considerable page download time because the most Drupal sites have blocks.

Block Cache can work individually for every block, and that is why it has great customizability. Cached blocks appear in the list of all blocks marked with  "[[-CACHED-]]". To include caching of some block, you should disable the main block and enable cached block.

Disadvantages:

Within styles, the module replaces blocks names with digits. I.e. you will see

<div class="block blockcahe-3">

instead of

<div class="block menu">

If styles were connected to block name, this can destroy your design…