I know I have brought this subject up before, but WP seem unable to make any progress on this issue which, for me, is becoming a real pain.
In a nutshell, if a post (or page) has a large number of comments (say 400) then posting a new comment can take anything up to 40 seconds!
I have tried everything to reduce this time, including:
1. Pagination of comments
2. No nesting of comments
3. No gravatars
4. No hovercards
5. No emailing
6. and of course Clear Cache, Clear Cookies and restart the browser.
I have given various reasons/excuses why it takes so long - none of them plausible. These include:
1. Its the time taken to render the page. No its not. I can render the page perfectly OK in a short time (Ctrl F5)
2. Its the time taken to check for duplicate comments. I wouldn't think so.
What I find significant (and this is what raincoaster saw some time back) is that if I comment on an old post with 400 comments, the time taken is more reasonable - around 8 seconds. This can be repeated about 5 or 6 times, BUT THEN it suddenly reverts to 40 seconds or more. Its as if WordPress suddenly notices traffic on the post and then starts doing something that takes an age.
The final bit of info is that while I am sitting twiddling my thumbs, waiting for my comment to appear, other users can see my comment! (which rather contradicts WP's reasons for the delay). Indeed, if I interrupt the wait (by hitting ESC) and then refresh (Ctrl F5) - hey presto! I see my comment.
The blog I need help with is brickiesgazette.wordpress.com.