I've been experiencing some strange, inconsistent audio underruns. The only consistent part is they occur during Digital Cut and when I'm on a deadline (of course!). I've only started experiencing them lately, after 3mos on MC2.52, but they're happening to different sequences in different projs. These sequences may share  a media clip or two (ie, sfx or a logo), but the underruns don't seem to hit near these shared clips anyway. I have scsi/lvd and fw drives hooked up though I only use the fw for omfs, etc and the scsi's exclusively for all Avid media. I tried dismounting the fw in case there was a stray file on it, but that didn't help.

If the cause is a corrupted file, wouldn't it also occur during normal playback? When they hit, they do hit in the same section, but what's weird is that they don't always hit. For example, I made a dig cut today of an entire sequence and it worked great all the way through. Then tried to make a 2nd dig cut of the same sequence, when it hung up on an underrun about 2/3 in. Tried dig cut again, hung again in same area. Then I tried to insert the dig cut from about two mins before the hang area through the end and it made it through flawlessly.

Other remedies I've tried are clearing the memory, rebooting, inserting the cut into a new sequence, but to no avail. I'm trying other steps next (adjust playlength, prefill, r/t stream limit), but again if it's corrupted files causing them, wouldn't they occur during playback, more often and consistently?

Any insight into this is greatly appreciated.

Just a couple of clarification questions.  Is the media involved in this digicut on the SCSI or FW drives?  What resolution?  1-1, DV25, etc...

All media in my cuts is stored on 18gb lvd scsi, save for one fixed 36gb ext scsi connected to the second slot of the scsi card.  I work on episodic TV and use 2 drives per project, recycling them when an episode is done. My dailies are dig'd off-site from the HDcam masters and the drives shuttled to me when ready.  Media used in every episode/project (ie music, sfx, logos) is kept on the fixed 36gb.  About 99% of all media I edit is 4m with a few clips at DV25.

At this point, to narrow down possible causes I've physically unplugged my FW drive to prevent it from even being seen by the G5. I'll re-connect it when I need to archive something or generate OMFs. Whatever is causing my underruns, I can't suspect the FW anymore.

Any thoughts?

Thanks.

It sounds to me like the drives can't keep up.  How are they striped together?  How many total LVD's?

I wondered that too, but I've completed six similar episodes/projects using this set up without incident, which points to a recent development. I have an 8-slot dock, currently full with 8 18gb drives, none striped. These are multicam projects and media is rather lo rez - 4m to save space - so striping isn't necessary. There are a handful of small clips dig'd at DV25 for visual clarity mixed in. The fixed 36gb scsi hooked to the other scsi port makes for a ninth drive.

In this particular dig cut, only three drives apply: primarily the two 18gb project lvds in the dock (dailies), plus a few select clips (sfx, vfx) from the 36gb. The other six online drives are not likely to be accessed unless a stray render somehow happened.

Since this problem has cropped up in two recent projects, I suppose it's possible that there could be something amiss within the individual drive pairs associated with each project, though it seems an unlikely coincidence.

In any case, how to explain the occurence only during dig cut? Whatever the cause, I can't get past why it wouldn't also occur whenever I play past the apparent n/g areas during normal editing.