8 mb used by PHP script only, mysqld uses other memory space.
If i have 50 requests per second for example and execution time about 0.2 sec it will eat about 50*8*0.2 = 80 mb average memory usage.
For example if your hoster have 2048 mb RAM, you using 4% of resources.

Read this topic. I have similar problem

http://www.joomlahacks.com/component/option,com_smf/Itemid,94/topic,1207.0

My hoster doesn't allow memory limit editing for security and stability reasons.
But i think something is wrong in integration, 8mb per request - too many

But i have troubles with 1.0.5 too. And only when patching joomla's index.php.

UPD:
I see blank page when requesting frontpage, SMF via Joomla, but most of pages are working. I have no idea how to fix it.

Hi all!
I have installed JoomlaSMFForum_1.0.2a on Joomla 1.0.5 and SMF 1.1 RC2
INSTALLATION CHECKLIST:
installed Install SMF Forum on the same database as Joomla.
done [un-patch] Patch mambo index.php file.
done [un-patch] Patch SMF index.php and Sources/Subs-Post.php file.
done [verify]  Synchronize Joomla and SMF users (optional).

I get the blank page when accessing to my site and this entry at error_log:
[Mon Jan 16 00:16:57 2006] [error] PHP Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 52 bytes) in /home/www/energy/includes/database.php on line 477
[Mon Jan 16 00:17:02 2006] [error] PHP Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 52 bytes) in /home/www/energy/includes/database.php on line 477
[Mon Jan 16 00:17:15 2006] [error] PHP Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 47 bytes) in /home/www/energy/includes/database.php on line 477
[Mon Jan 16 00:17:49 2006] [error] PHP Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 64 bytes)

When i un-patching Joomla's index.php site works fine.
Upgraded Joomla to 1.0.6, problem doesn't solved.
Tryed to use bridge from SMF developers (3.20) - it have similar problem after Joomla's template modification.

Is there a solution to get it work?

Thanks.

It's not  bug, it's feature
Seriously, it makes problems only when you use "Who online" module adapted to work with SMF. So you can't send PM to member that has been never logged to SMF (nat all my users using forum) clicking on PM-icon near user's name in this module.
In other cases user's account in SMF will be autocreated while first time login to forum using login and password from Mambo.

I have same problem. But it seems, new user in forum will be autocreated while user's first time login to forum.