Memory - allocation & monitoring

http://msdn.microsoft.com/en-us/windows/hardware/gg487508

Out of curiosity, why are you researching this?

Here’s the net-net: XP can normally only provide up to 2G of memory per application. The /3GB switch allows certain applications, provided they were written to take advantage of this, up to 3GB of memory. This is only recommended if you have more than 3GB of physical memory in the machine.

As far as monitoring goes, there are plenty of ways to determine this. Built into Windows is the application called perfmon, which will do this for you. It’s a crappy application, though, so I wouldn’t recommend it. (It hasn’t really been changed since Windows 95, if that says anything.)

If you right mouse click on the task bar you can bring up the task manager. It has a tab that shows used memory. It also shows how much is swapped out. You might actually be exceeding your swap file. If your hard drive is going crazy even when the song is stopped, that would be an indicator.

This is called overcommit and is one of the differentiators between a multi-tasking operating system (like XP) and the old school ones like DOS. Overcommit is a feature that (oversimplified) allows least recently used programs and memory to be swapped to disk so that new programs and new memory can be loaded / used.

The problem here is that if the programs / memory that was swapped out then gets referenced it needs to be swapped in again, meaning that it replaces another program / memory. If those get referenced, etc. ad nauseum you end up with constant swapping-in / swapping-out. This is called thrashing and is a huge performance bottleneck since Windows essentially freezes everything while swapping in or out is being performed.

None of this may be relevant. I just thought you may be interested in knowing. :smiley:

Under Task Manager, Page Faults is an indicator of how many times memory is referenced that isn’t actually in memory at the moment.

Or, you could start a bunch of “We need better FREEZE” threads. Always too few of those in these parts.

Because people are LAZY! Clicking one button without understanding what’s going on inside the audio engine is always preferred method to 99% of the people.

EDIT: Excuse me for my quite offending choise of expressing myself. In general, I think ‘Freeze’ is a nice feature (while I’ve never used it).

LOL, you actually get the joke … that’s exactly what I say in those threads. FREEZE is bounce for morons.
EDIT: oops that could be read wrong … not inferring anything.

:smiley: … I tried to be at least semi-diplomatic with my answer :laughing:

hehe, I might have been just a hair over the top :wink:

Are you sure your Physical Memory Total number is correct?

Physical = 340,689
Available = 1,540,900
System Cache = 1,283,668

Something isn’t right here.

Looks like he missed a zero somewhere!

This doesn’t sound like an overcommit problem.

No, perfmon is only reporting what Windows is saying. It does nothing on its own other than draw a graph. The technical details behind this are beyond the scope of this discussion. :smiley:

It sounds more like a driver problem or maybe a bug in the ASIO subsystem, i.e. perhaps “garbage collection” (a Comp. Sci. term) isn’t happening as often as it should be.