Dropped frames with DeckLink HD Pro PCIe + Xserve RAID + Final Cut Pro 5.0.4

I've got a really sad situation where I have dropped frames about every 20 to 40 seconds in high def capture. Worse: I have TWO workstations identically configured, one of them worked fine in the start and now it has the behavior as the second one, which never captured more than half a minute without a drop.

Here's what I have (times 2):

Power Mac G5 Quad 2.5 with 4GB RAM
Mac OS X 10.4.6
QuickTime 7.1
Final Cut Pro 5.0.4 + Xserve RAID update (latency stuff)
Decklink HD Pro PCIe + Decklink 5.5.1 Driver
Apple Fibre Channel PCIe Card
14-disk (7TB) Xserve RAID with 512MB cache per controller, Striped RAID 5 + RAID 5 (about 5TB free), 32K RAID Block Size, 8 Stripes drive cache


Here's what I've already tried:

1. Captured 23.98psf HD uncompressed 10-bit to root of RAID volume
results: failed (dropped frames about every 30 seconds)

2. Captured 23.98psf HD uncompressed 8-bit to root of RAID volume
results: same as above

3. Captured 23.98psf HD DVCPRO HD to root of RAID volume
results: same as above

4. Captured 23.98psf HD DVCPRO HD to Startup Volume (Macintosh HD)
results: success (no dropped frames)

Interestingly, hoping things were simpler to solve, I've even tuned FCP to limit the capture file sizes to <2GB and still it doesn't work.

I was going to set the drive array to RAID 0, but RAID 5 should be fine for this. It doesn't seem to be a throughput question, once DVCPRO HD also dropped in test #3 (see above).

Any ideas?

ANY tip or suggestion would be of great help. In the meanwhile I'll try to reinstall fresh system on both of them and use an older set of driver+OS.

Thanks in advance!



Cesar Hashimoto

Hey, I'm not THAT dumb. ;o)

The 2 arrays were striped together as ONE big 5.5TB volume using disk utility. So it is a RAID 50 setup. In fact it has the same configuration as many other uncompressed HD FCP workstations I've setup. But none of them were PCIe with QuickTime 7.1. They were AJA Kona 2, actually.

I did run the Blackmagic drive speed test and it returned about 300MBps for read and about 250MBps for write (not exactly but it was pretty much like that). That is well beyond the minimum througput necessary for 10-bit 4:2:2 uncompressed HD @ 1080p24 (which is about 125MBps). In fact, the results showed "25fps" for disk write @ 1080p24. And because the volume is fresh new, there shouldn't be any bottleneck. Not for 30 seconds!

Did you read where I say the array wasn't able to write the 100Mbps DVCPRO HD stream, and the internal SATA drive did handle it well? It isn't just a matter of throughput.

There are many variables, unfortunately: QuickTime 7.1, Mac OS X 10.4.6, and the new PCIe bus, which is a big bet here. And I also read that Blackmagic Design didn't test QuickTime 7.1 yet, so we'll try to step down and do it again.

Back to work! :o) Any other tips?

Thanks anyway, Bob.

Cheers!

Cesar Hashimoto

http://www.apple.com/support/downloads/quicktime704.html





regards

Kristian Lam
Blackmagic Design

how much room is left on your XServe RAID - is it almost full ?

bob Zelin

Thanks all for the help. Including the BlackMagic Design support team.

After many, many trials, we've come to the fact that one of the controllers was misbehaving. It is now working full power.

Cheers!

Cesar