Bounce to Disk and Quick Start Delay bug solved

aaronlyon · Post by **aaronlyon** » Fri Jun 02, 2006 2:00 pm

In DP 5 and 5.01 I have been suffering from a Bounce to Disk bug. When trying to export selected soundbites from the Sequence window, the first half-second of the exported audio is silent. I finally figured out that if you disable the check box "Pre-fill file buffers for Quick Start Delay" in the Configure Studio Settings dialog, the problem goes away.

-aaron

Frodo · Post by **Frodo** » Fri Jun 02, 2006 2:06 pm

Bravo, Aaron.... and thanks!

Shooshie · Post by **Shooshie** » Fri Jun 02, 2006 4:08 pm

Totally counter-intuitive. Maybe I haven't had the problem because I haven't had that checked, but if I DID have the problem, I would not have thought of that as the cause!

Shooshie

demonsp · Post by **demonsp** » Sat Jun 03, 2006 8:25 pm

I've been noticing from my own experimentations with DP, there seems to be an issue with how RAM is handled. (have written to MOTU)
That's why I think some people (myself included) have reported problems with large buffer sizes (1024 upwards) and now the "prefill file buffers" option.

From looking at how much RAM is used (using monitor utility) there seems to a large amount of virtual RAM being used instead of "real" RAM.
I'm no programmer, so I'm just expressing these thoughts as an idea.

Could it be possible? As I remember from OS9 that Virtual RAM is no good for DAW applications.
Ideas?

Frodo · Post by **Frodo** » Sat Jun 03, 2006 10:04 pm

OS X uses an "intelligent" process that writes data references to Virtual Memory that could be "potentially" used so that when they are called for, this data can be paged in and out of RAM and virtual memory as needed. It leaves a quantity of real RAM open for other immediate processes, but it doesn't load everything into RAM as with OS9-- otherwise we'd easily max out our resources a lot sooner. Without VM, the search for data and getting that data to the CPU would take longer and result in slower performance, or at least the impression of slower performance.

The term Apple is using is "pre-emptive multitasking". This is a lot different from OS 9 when whatever RAM you manually had to assigned to an app you eventually got the "out of memory" warning. OSX has taken steps to avoid this annoying limitation by making better use of VM.

From MacWorld, July, 2001

The preemptive multitasking and virtual memory capabilities of OS X's BSD core, where the CPU will be called upon to regulate computing time between a variety of applications and processes, would have proven too great a challenge for a third-party developer to combat. (Under previous versions of Mac OS, most sequencer developers have required that virtual memory be turned off.) Moving these services inside the OS frees developers to concentrate on enhancing their interfaces and adding post-production capabilities.

Among the factors which impact on how well this works are:

1. How much the user is asking the computer to do at any one time-- running lots of VI's, long hi-res QT's, several reverbs and CPU intensive plugins will bog down the fastest systems quickly.

2. What kind of computer is being used, of course.

3. How much RAM is installed.

It does pay to understand just how much your system can handle. My projects since at least Panther have been a lot more intense. I used to run tons of MIDI tracks in OS9, but all my instruments were hardware-based. This made it easier for the computer to deal with just audio files and MIDI data. Now, most of what I'm doing is virtual with some outboard MIDI gear. Yes, there are high, sustained CPU readings, but a few minor adjustments eliminated the spikes. I don't worry if the CPU meter is running at 80-90% as long as it's performing smoothly. Latest adjustments to templates and VI optimization give me a current average CPU peaks at about 60%.

I wouldn't say it's "bad" for DAW users at all. There is always a push for more resources, and since Apple has taken over E-magic, I believe that they are that much more in touch with what DAW users need-- and want. Granted, non Apple companies (like MOTU) will always have to stand in line behind Logic in terms of Mac optimization and compatability, but the residual benefits for Mac users IS there.

I'm not looking forward to the Intel *transition* because it might not be a smooth or pretty change-over. But I am looking forward to when Macs can handle a bit more than they do now and do it more stably. Hardcore users of VI's have not hesitated to setup farms and networks of Macs and PCs to accommodate huge and demanding projects, but a few VI's, a 15 minute QT movie, a half dozen effects plugs in DP is a very reasonable workload for today's machines. But 200 tracks of MIDI, 40 tracks of audio, and 30-40 VI's is easily a three-computer setup-- and bigger projects are not that uncommon.

The big question is "how much can we do on one single machine?" The answer: what kind of machine is being used, how well equipped it is, and just "how much" is "how much"-- or how much is "enough"?

All I know is that "enough" is never enough.

RCory · Post by **RCory** » Sun Jun 04, 2006 12:15 am

I,too, have been experiencing the blank audio in the beginning of bounces... I'll try the disabling quickstart option and see if this solves it for me.

demonsp · Post by **demonsp** » Mon Jun 05, 2006 8:41 pm

Thanks Frodo for the informative reply; =)

I can see your points and understand we're all swimming in new territory. (New macs, new OS, etc)
Things seem to change everyday and I sympathise with developers. Must be challenging work.

Here's hoping things keep improving.

Cheers!

kelldammit · Post by **kelldammit** » Mon Jun 05, 2006 10:10 pm

demonsp wrote:Thanks Frodo for the informative reply; =)

I can see your points and understand we're all swimming in new territory. (New macs, new OS, etc)
Things seem to change everyday and I sympathise with developers. Must be challenging work.

Here's hoping things keep improving.

Cheers!

y'know, that is exactly what set this place apart from so many others.
bless you.

kell

Frodo · Post by **Frodo** » Mon Jun 05, 2006 10:26 pm

kelldammit wrote:
demonsp wrote:Thanks Frodo for the informative reply; =)

I can see your points and understand we're all swimming in new territory. (New macs, new OS, etc)
Things seem to change everyday and I sympathise with developers. Must be challenging work.

Here's hoping things keep improving.

Cheers!
y'know, that is exactly what set this place apart from so many others.
bless you.

kell

demon and kell--

You guys are royalty, and you ask great questions which spur me to seek the same answers, if they are out there. I learn as much from people's questions as I do from their answers.

I must say, I really like the vibe of this place. There's always been something cool about DP users since the earliest days of U-nation gave us a place to meet and trade notes. This place has given me so much that I only hope to give back where possible without overdoing it...

aaronlyon · Post by **aaronlyon** » Thu Jun 08, 2006 11:33 am

A follow up...

I returned to the same project to make an audio edit and export a sound bite, and was bit by the same bug, even with PreFill OFF. I had to toggle it ON, and then back OFF to get the fix.

-aaron

demonsp · Post by **demonsp** » Sun Jun 18, 2006 11:09 pm

Interesting Aaron...I'll keep that in mind.

Frodo: Thanks for the kind words.