More jerky symptoms

[Kristian Lam]

Hi Mark,

Could this be a drive speed issue? What sort of storage are you capturing and playing back from? Have your tired the Disk Speed test and what results did you get?

regards

Kristian
Blackmagic Design

[Luke Maslen]

Hi Mark,

We’ve seen a number of instances where a disk speed issue has caused “timecode break” warnings. Even if your disks are usually fast enough, you might observe this error if your disks are beyond a critical capacity theshold (eg 80% full), or have become highly fragmented from many batch captures or if antivirus software is slowing down your Mac. It is worth considering these factors even if a disk benchmark seems to indicate adequate performance.

Regards,

Luke Maslen
Blackmagic Design

[Mark]

Hey thanks guys. I have a swiftdata in the g5 and this project is using a raid 0 with about 39% of capacity available but does seem a lot slower than when I first installed it. I am getting read-70 write-40 (slower than my offline Lacie Big disk) So would you suggest Disk warrior? I really haven’t been defragging much in the past couple of years.

[Kristian Lam]

Hi Mark,

The best way to “defrag” will be to move everything out of the drive. Reformat, then move the back in.

Drives will slow down (sometimes very dramtically) as they get filled.

regards

Kristian
Blackmagic Design

[Luke Maslen]

Hi Mark,

I’m a big fan of DiskWarrior but it is not used for defragmentation of files. Kristian’s suggestion of copying files off on to another disk, then erasing the RAID and then copying the files back on would be the fastest and safest way of defragmenting the disk. There are a few file optimization utilities available but they take a very long time to move large video files around and I’m not aware of any of them being fail safe. DiskWarrior will sometimes provide a speed boost as it optimizes the directory structure, which is worth doing, but that is different to optimizing the location of the files on the hard disk.

As a single SATA disk reaches about 80% capacity, it may slow down to around 50% of its speed when empty. This is normal and the more disks you RAID together, the less this slow down will be. A lot of DeckLink users are using 2-disk SATA arrays and these are usually fine but can still underperform when they become too fragmented. It is useful to have a spare disk or two available so you can copy files of the disk array and erase it periodically if it is becoming too slow.

Regards,

Luke Maslen
Blackmagic Design

[Mark]

Thanks guys… well I have had some drive problems in the past month …(one disappeared from the raid and left the material on it lost in it’s wake) and now I notice that even when I completely reformat the drives and stripe again, I am getting pretty slow write speeds… 50 vs read @ 120 and still getting the jerky captures with 99% of the drive capacity available. Do these drives wear out? Geeez only had em a year or so.