How much does a high "Number of Posts to Show Per Page" setting slow down SDMB?

If a lot of people have this option set to a high number (such as 100 posts per page), how much would that slow down the board? After all, it is pulling actual data from the database, as opposed to reporting just a simple number. Are there any stats for how many people on SDMB have a high “Number of Posts to Show Per Page” selected?

I used to have it set to 100. Most threads would fit within that parameter, so why not? It sure does make things easier to read, with less clicking. But if a lot of people do that, I think a problem could surface.

But what I just did was install a Firefox add-on, called AutoPager. What it does is load INLINE the next page of a thread, once you have scrolled down to a certain part of a thread. So, if I don’t like a thread, I won’t have used excess bandwidth or processing time on the SDMB server by loading data I don’t need.

I currently have it set to 40 posts per page. I could probably set it lower, and I might. I had to make sure that I turned on Smart Paging.

Anybody else use this add-on? Do you think that if more people did this on SDMB, it would help out the website in any way? If it does help out the website, what other settings can I adjust, either in the SDMB’s User CP, or via another add-on?

I have posts set to 200. I’d think that having it set to fifty and needing to call for several new pages would be far more server work. No idea how this compares to the add-on.

I have it set to 200 as well. I never really figured it was making the board run slower. I don’t think it SHOULD matter, however it might. Still, if it was a problem that attributed to any poor performance of the boards, you don’t think they’d keep it on as an option, do you?

If they had a higher posts per page, I’d probably use that, too.

I imagine it’d depend on your browsing habits, which might vary from thread to thread. If it’s a thread that you’re coming back to often, then each time you load it, you’d be downloading the entire thread, rather than just the last page or maybe two. In that case, you’d be better off with a small number of posts per page. On the other hand, if it was already a long thread when you came to it, and you posted once and then left, you’d be saving whatever overhead is associated with loading a new page, so in that case, a large number would be better. I don’t know what the cutoff is.

It’s also worth pointing out that simply increasing the number of rows you’re fetching from one table on a single index is among the most efficient operations in modern databases and the impact on constructing the page isn’t much more complicated than pasting data in a loop. Each additional page load means more session handling and whatever else vbulletin goes through to initialize in php.

I would guess that if the matter in question is helping out the administration, speaking generally, the factor with the most effect would be that guests appear to see the same number of ads per page regardless of the posts per page setting.

What do the administrators of SDMB think about this idea? What do the moderators think?

I assume that if the 200-posts option was detrimental to performance, the administrators would turn it off. :dubious::wink:

That’s if you need all those rows anyway. If you only need 50 rows, retrieving 200 every time would be a waste of database resources.

So if a person often only looks at the first page of a thread, decides s/he is not interested, and leaves without reading the rest, then only retrieving 50 rows at a time is beneficial.

On the other hand, if you are the type of poster that always reads every post in a thread, then retrieving more rows at the same time would be better.

One could come up with a variety of different scenarios and argue the pros and cons of each. But, in short, the most efficient way is to retrieve only the rows you need.

Explain to me again how you’re supposed to know you want to read a whole thread without, you know, reading that thread.

Another consideration is that if you’re returning to a thread that’s at the 155th post, and you’ve read the first 150, you only need to load the last 10 posts. If you’re set to load 200 at a time, you have to sit and wait while the board loads 150 posts that you’ve already read, and don’t plan to re-read.

I find 50 and 200 load at about the same speed. Are you on DSL or dial-up?

Was that question for me?
Here’s an example of what I mean:

I open a thread titled “The most exciting thing happened to me today!”
The first post says “My kitten ran up to me and started licking my face without any prompting whatsover.”
Second post says: “How cute! Pix please!”

After reading the second post I know I can bail out of the thread and I probably won’t be missing much that I personally would care to read.

Damn Skippy, most of us would’ve figured that one out on the mouse over.

:smiley:

My point is that you can’t know what the second post is until you open the thread. Over the long run the optimum strategy will always be to open the thread for the maximum number of posts. (And that’s because of mouseover, since you already have a good indication of whether you will want to read further before even opening the thread.)

As others have said, getting the server to retrieve 200 posts is a trivial bump over any smaller number. It’s getting the server to serve at all that requires the most effort. So multiple smaller uses of the server will always be a heavier load than one large one.