10.9.9 Tuning Gnus

Question 9.1:		Starting Gnus is really slow, how to speed it up?
Question 9.2:		How to speed up the process of entering a group?
Question 9.3:		Sending mail becomes slower and slower, what's up?

Question 9.1:

Starting Gnus is really slow, how to speed it up?

Answer:

The reason for this could be the way Gnus reads it's active file, see the node "The Active File" in the Gnus manual for things you might try to speed the process up. An other idea would be to byte compile your ~/.gnus (say `M-x byte-compile-file RET ~/.gnus RET' to do it). Finally, if you have require statements in your .gnus, you could replace them with eval-after-load, which loads the stuff not at startup time, but when it's needed. Say you've got this in your ~/.gnus:

(require 'message) (add-to-list 'message-syntax-checks '(sender . disabled))

then as soon as you start Gnus, message.el is loaded. If you replace it with

(eval-after-load "message" '(add-to-list 'message-syntax-checks '(sender . disabled)))

it's loaded when it's needed.

Question 9.2:

How to speed up the process of entering a group?

Answer:

A speed killer is setting the variable gnus-fetch-old-headers to anything different from nil, so don't do this if speed is an issue. To speed up building of summary say

(gnus-compile)

at the bottom of your ~/.gnus, this will make gnus byte-compile things like gnus-summary-line-format. then you could increase the value of gc-cons-threshold by saying something like

(setq gc-cons-threshold 3500000)

in ~/.emacs. If you don't care about width of CJK characters or use Gnus 5.10.0 or younger together with a recent GNU Emacs, you should say

(setq gnus-use-correct-string-widths nil)

in ~/.gnus (thanks to Jesper harder for the last two suggestions). Finally if you are still using 5.8.8 or 5.9 and experience speed problems with summary buffer generation, you definitely should update to 5.10.0 since there quite some work on improving it has been done.

Question 9.3:

Sending mail becomes slower and slower, what's up?

Answer:

The reason could be that you told Gnus to archive the messages you wrote by setting gnus-message-archive-group. Try to use a nnml group instead of an archive group, this should bring you back to normal speed.