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if you have 4gb of ram, what settings for ram do u think?

Posted: Tue Sep 16, 2008 10:46 am
by queglay
I just wanted to check what maximum preload mem size you guys usually set and your other ram settings should be set to if you have 4gb of ram.

its all a bit new to me and its hard to determine whats optimal.

Re: if you have 4gb of ram, what settings for ram do u think

Posted: Wed Sep 17, 2008 9:57 pm
by david
Hello Queglay,

queglay wrote:I just wanted to check what maximum preload mem size you guys usually set and your other ram settings should be set to if you have 4gb of ram.

its all a bit new to me and its hard to determine whats optimal.


On Leopard, the "Start releasing media" should be 60%-70% to leave room for other app to run otherwise OSX will begin to swap/paginate (transfering part of memory to/from disk).

For the other settings, it will depend on what you usually put in your composition.

You can change each media settings afterward :
- direct to disk : the media will be read from disk and decoded when played
- ram preload : the media will be preloaded in memory and decoded when played
- ram preload uncompressed : the media will be read from disk and decoded in memory, and then read from memory

Direct to disk cost almost nothing in memory but will use some disk bandwidth.

Ram preload will cost 0 disk bandwidth but will cost some CPU time when played

Ram preload uncompressed cost 0 disk bandwidth and almost 0 CPU time but uses a LOT of memory.

So Preferences helps you put your media in Ram preload or Ram preload uncompressed but you could (should) change the "preload" settings (independently for each media) depending on how you will use your media afterward.

David.

Posted: Thu Sep 18, 2008 8:07 am
by queglay
thanks for the tips david, its all very handy to know. can't wait for my gig tommorow.

Posted: Mon Nov 17, 2008 3:42 pm
by spectral
I am a long time user but this still makes my head hurt...;-)

Now most of us lucky semi-pro users will have 4GB of RAM in out MacBook pros....so the original question which is what to set the maximum preload memory size at in Mbytes?

but hey a 32bit program can use 2GB of RAM.....or can modul8 be allocated as much as you like ?

Posted: Mon Nov 17, 2008 4:04 pm
by david
Hello spectral,

Modul8 is a 32bit program and as such could use 4GB. But these 4GB are for user data AND kernel/OS/frameworks data/code. In practice, a 32bit program could use 2-3GB depending on how much data the system part (OpenGL driver, Mach kernel, ...) is using.

If you launch the "Activity Monitor" application, you will see "Real Memory" and "Virtual Memory" (VSIZE). Virtual Memory is what could not go beyond 4GB.

If the VSIZE comes too close to 4GB, Modul8 could crash due to OpenGL/QT or other frameworks having problems allocating their memory.

The default preferences are : 60MB/60%/128MB

You could experience with higher values for the 3rd item. Then look at the Activity Monitor for Modul8 VSIZE and the console for messages indicating allocation failure :

17/11/08 14:36:35 Modul8[1592] Modul8(1592) malloc: *** mmap(size=1228800) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug

If you have "only" 4GB, remember that other applications would also need some memory to run. If you come too close to 4GB, you could experiment some slowdown as other app are requesting memory and OSX is then transferring (paging out/in) some of Modul8 memory to disk.

David