Do disabled Drupal modules affect performance?

Question

Does having Drupal modules installed but not enabled have any effect on the performance of a Drupal site?

To put it another way.. Would removing disabled modules from a Drupal site have a positive affect on performance?

Answer 1

Essentially, there's no effect on performance from disabled modules.

The only exception is when Drupal checks for updates or builds the list of available modules. These will only ever affect the occasional cron and the administration pages that display all the available modules.

Answer 2

They do affect performance. See this issue: http://drupal.org/node/329012