Playback slowing down – PPro

[Bill Buchanan]

If yours is a gradual slowdown rather than stuttering/dropped frames, then I don’t know. But, if stuttering/dropping frames, then you probably have a problem with your SATA array. I recently ‘fixed’ my slow Seagate SATA array by determining that one of the drives was (or had become) significantly slower that the others. As you probably know, the xfer speed of an array is determined by the slowest drive. I had to delete the array and test each drive individually to determine which one (or more) was the bad guy. One drive Read tested about 20-25mb/s and Write tested about 52mb/s while all the others ran about 60-65mb/s Read and Write. I replaced that drive, and now the array tests at the rate it should.

Bill Buchanan

[Bill Buchanan]

I should have mentioned that mine was a RAID 0 array, too.

Bill Bucanan

[Lukimon]

Thanks Bill. I guess that’s a possibility – I’ve already had to replace one bad drive, losing everything of course (almost, could salvage a lot before wiping the array), so the new array is only about a month old, and I tested each drive before creating the array as well and both were what I expected (have about 7 seagates). The ‘slow down’ is gradual, but fairly quick, not like simply dropping frames – the waivering pitch of the audio sounds like piano music on an old 16mm student film from the 80’s, if you know what I mean – that’s the wierd part – actual playback speed is affected, not just the playback framerate.
And it happened after installing the latest drivers.

[Skip Cercelletta]

Try dumping the corrupted preferences.

[Lukimon]

Thanks for the suggestion, but no, didn’t help. What I’m working on is a music video, and when I play the audio track in the source window it sounds right, but when from the timeline, it’s like there’s just no consistancy in the time/speed/pitch – only slightly though most of the time. occasionally it slows right down…

Slow hard drives would only affect framerate, not actual playback speed wouldn’t they?

Any BMD people got any ideas?

Cheers.

[Matt Dowling]

Does this happen with video and audio from tape? As in a clip captured via Digibeta?

You are using one of our presets right?

The only thing i can think of right now is have you changed the audio interleave in the sequence settings?

I’ll keep thinking..

Cheers,

Regards,

Matt
Blackmagic Design

[Lukimon]

Thanks for the response, Matt. The preset I’m using is the Blackmagic 10bit 16×9 PAL.

It seems to happen no matter what’s playing from the timeline, as in raw captured clips, rendered clips (all renders going to the capture array), and shots exported from After Effects (using BMD 10bit codec). The audio is from an aif given to me by the artist. Strangely playback is also affected when playing the video clips in the souce window, so not just the timeline.

It’s just I’ve been working on the clip for ages and it only occured after I installed the newest drivers days ago. Apart from that I hadn’t changed a thing.

Can I provide any more info?

[Lukimon]

As an update, i think it might be a CPU thing. Anyone know if too much strain on the cpu can cause this type of effect?
I’m trying to work out what might have happened, it’s an Athlon64 3500 Newcastle chip, Asus A8V deluxe mb, all seems to be running at the correct frequencies…

[Lukimon]

Just in case anyone was still thinking about this – I’ve discovered it also is happening on dv projects, so it’s not a decklink thing.
Now I really have no idea…
But thanks for your responses.