gnus is just slow when dealing with more than 5000 articles

[Francis Moreau]

hello,

Does anybody know some gnus tricks to make it faster when dealing with a
group with a lot of articles ?

The time to fetch headers from the news server is ok but the time to
summarise the buffer is way too long. The same when trying to filter the
summary buffer.

Thunderbird deals with 17000 articles and all operations (searching,
sorting in threaded view...) is almost instantaneous.

thanks
-- 
Francis