We're all right. It is a desert topping and a floor wax.
You are correct Oliver, in the traditional sense, there is no way a 32bit application or OS can see more than 4GB of RAM as far as I know. But as Terry states, there are benefits to running a 32bit application in a 64bit environment.
On the PC side, it is the only reliable way a 32 bit application would have access to its fully permitted load of RAM because the OS is not eating into it. Every 32bit application can each get up to 4GB or RAM and the OS along with its drivers can get as much as it wants, rather than splitting it. Plus the OS and any 64bit stuff gets a nice big fat pipe to resources like RAM. A big deal.
To make things more complicated I believe some plug ins and or modules like Marquee actually run as separate processes. Some should have access to their own allotment of memory and resources. Happens under the Composer banner but really are separate threads to the CPU and memory.
What I was getting at is that no application exists on a island. It makes all sorts of calls to the OS, the kernel, drivers, extensions, libraries, caches, other processes, etc. The functioning of that stuff does affect the performance of the application and the computer as a whole.
On PC side, think about how crash happy the Avid is when the old 3GB switch is installed or when certain things are going on with storage drivers, registry entries and video card drivers.
Even though your video card or other devices have their own physical memory it counts against the OS's allotment of memory because it is really all about addressable space not physical RAM. The OS, drivers, and etc sort of pre-reserve chunks of main memory.
If the OS or kernel manages the reservations. Ff it gets squeezed, bad things happen. All that stuff will have far fewer resources available in 32bit mode. The OS itself and all of its native services will be limited to how much RAM it can see and use. It also has to use a narrower path to it and the CPUs.
Maybe it slows things down with more frequent swapping of memory content, or in the case of some drivers it is a crash when they intrude on something else's space or run out memory.
Perhaps this has something to do with the "segmentation fault main thread" or the "bus" errors which are presently frequent in OS X Composer. Just a guess. Over my head.
Forcing OS X to conduct core business in a 32 bit environment does have to reduce performance or capability to some degree compared to a full 64bit OS. Probably would show up most in multi-tasking or things which push the kernel, host services or drivers.
The fact that OSX somehow lets 64bit applications run as 64bit while the OS is in 32bit mode confuses things some. On some level there has to be a difference or some sort of abstraction layer. Not sure exactly what it would be. Would love to hear more about exactly how this works if anyone knows.
I think in case of OS X the 32bit kernel uses address space re-mapping (as can windows) to allow the 32 bit OS and 64 bit applications hosted on it to use more memory than 4GB. But that would NOT be same as native 64bit processing.
It is more like virtual memory. Yes it is RAM but there is some detouring, management, overhead and redirection involving the kernel. And it all happens in a 32bit wide path. Think it can be buggy too. Think that is why 32bit Windows folks stay away from it.
And from there it gets a hell of lot more complicated and way beyond my understanding.
If anyone can correct, improve or elaborate on my general assumptions, it would be very welcome.
The bottom line is there are only 2 items which force me to boot my shiny 12 core Mac in 32bit mode...that is the Avid dongle driver and the Facilis MultiWrite driver.
Would love to stop doing that.
Reminds of the old 4-6-8 Cadillacs. I paid for all 8 cylinders. Would love to have them firing all the time.
Chris MagidRTVF
--- On Mon, 11/15/10, avid_curren <tcurren@aol.com> wrote:
From: avid_curren <tcurren@aol.com>
Subject: [Avid-L2] Re: Preferred Symphony platform
To: Avid-L2@yahoogroups.com
Date: Monday, November 15, 2010, 8:35 AM
The 64 system bit allows Avid to access the full 4 gigs of memory. When you work in long effects laden sequences, it makes a huge difference.
--- In Avid-L2@yahoogroups.com, Oliver Peters <oliverpeters@...> wrote:
>
> Chris,
>
> > chris magid:
> > This was part assumption and part conjecture on my part. I may need to be corrected.
> > The 64 bit kernel and 64 bit EFI do seem peppier to me when we are able to run them.
>
> You may be absolutely right and it sounds like you've done some tweaking. But AFAIK, a 32-bit app doesn't access anymore memory if running in the 64-bit kernel. That's a function of how the app is coded. It would be nice if someone from Avid chimed in to clarify. I'm referring to OSX only, since I'm not sure about the Win configurations. There may be some tweaks Avid has done that affects this. Thanks.
>
> - Oliver
>
[Non-text portions of this message have been removed]
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