Add setmemorymax for 3 scripts running together ?

[Music Fan]

Hi,
I'd like to run 3 scripts at the same time (because CPU usage is around 30 % for each) and I'd like to know if there is a crash or bug risk if I don't add setmemorymax function.
What could be a good value in this case ?
I have Windows 7 64b with 4 GB of RAM.

[foxyshadis]

As long as each individual script doesn't crash, running them side-by-side won't crash or change the output (barring plugin bugs). Watch your memory use, though, because if you exceed your free physical memory you'll get a lot of disk churn, which will hugely degrade your encoding speed.

[Music Fan]

Ok thanks, the memory used by Virtual Dub when encoding 1 of these scripts in Lagarith is around 620 MB.
In which case is it recommended to use setmemorymax ?

[foxyshadis]

Even 4-5 of that would comfortably fit into 4GB, so no worries.

SetMemoryMax only restricts AviSynth's caching, not any plugins, so it's only a small difference in many scripts. You shouldn't mess with SetMemoryMax unless you actually are running out of space; a reasonably large cache is helpful in most scripts.

[Music Fan]

Ok, does it mean AviSynth 32bit is Large Address Aware ? If it isn't, is each script limited to 2GB max, even if several scripts running together can use more than 2GB ?

[Groucho2004]

Ok, does it mean AviSynth 32bit is Large Address Aware ? If it isn't, is each script limited to 2GB max, even if several scripts running together can use more than 2GB ?
32 Bit Avisynth (i.e. avisynth.dll) itself isn't Large Address Aware. A 32 Bit application that uses Avisynth needs to be LAA in order to address up to 4 GB (on a 64 Bit OS).
When you run 2 or more encodes simultaneously, they all have their own address space and are therefore independent. How many simultaneous encodes you can run is largely determined by the available memory.

[Music Fan]

Thanks, a few more questions to be sure I understand correctly ;

A 32 Bit application that uses Avisynth needs to be LAA in order to address up to 4 GB (on a 64 Bit OS).
Ok, thus if Virtual Dub is LAA, a single script can use more than 2 GB, even with Avisynth 32 bit ?
But if I specify setmemorymax(512), the script won't use more than 512 MB, whatever Virtual Dub is LAA or not ?
And I guess that the program using the script (Virtual Dub for example) also needs some memory that is added to the quantity of memory used by the script (for a total of 512 + this quantity), right ?

[Groucho2004]

Ok, thus if Virtual Dub is LAA, a single script can use more than 2 GB, even with Avisynth 32 bit ?
Yes, but only on a 64 Bit OS.

But if I specify setmemorymax(512), the script won't use more than 512 MB, whatever Virtual Dub is LAA or not ?
Read foxyshadis' reply again -> "SetMemoryMax only restricts AviSynth's caching". Some filters use a lot more than that.


And I guess that the program using the script (Virtual Dub for example) also needs some memory that is added to the quantity of memory used by the script (for a total of 512 + this quantity), right ?
Correct.

[Music Fan]

Read foxyshadis' reply again -> "SetMemoryMax only restricts AviSynth's caching". Some filters use a lot more than that.
Ok, I didn't realize filters were not included in this total.
And when I look at the quantity of memory used by Virtual Dub in the task manager, does it include everything used by avisynth, the script (and its filters) and Virtual Dub ?

[Groucho2004]

Ok, I didn't realize filters were not included in this total.They are as far as I know but I have seen scripts using 2 GB of memory even though SetMemoryMax was at the default 512 MB, especially with SEt's AVSMT.
I'm not sure why, have not tried to figure it out (yet) and I never use these monster scripts like MCTD.

[Groucho2004]

And when I look at the quantity of memory used by Virtual Dub in the task manager, does it include everything used by avisynth, the script (and its filters) and Virtual Dub ?
Yes, it does. For a detailed process analysis I recommend you use ProcessExplorer.

[Music Fan]

Thanks, last question : how to know the maximum quantity of memory that will be used by Virtual Dub (I mean for one script) ? Because in the task manager, when playing a script in Virtual Dub, this quantity increases. Does it reach a limit after a certain period ?

[Groucho2004]

Thanks, last question : how to know the maximum quantity of memory that will be used by Virtual Dub (I mean for one script) ?
No way to know in advance, too many variables - script, filters, resolution, threads,...

Because in the task manager, when playing a script in Virtual Dub, this quantity increases. Does it reach a limit after a certain period ?
One can only hope. :D

[Music Fan]

Yeah, fortunately my pc hasn't yet exploded :scared: ;)