A gradual slowdown

[Eric Emerick]

Here's the issue: Plain and simple, the longer I edit on my '08 MacPro with 10GB RAM, the slower it gets. It is project and resolution independent. SD, HDV, XDCAM all act the same. The cores are not acting strangely according to MenuMeter. If I stop, reboot and re-open the project, it's like starting over. It's fast and gets gradually slower. To the point of a spinning beachball for as long as 10 or 20 seconds, sometimes longer. I should specify that it is playback that is slow, not rendering. Unlimited or Safe RT is no difference. Also, my project media files live alone on an internal 3TB software RAID 0. I have used ext. FW 800 as well, same thing happens. Any ideas are greatly appreciated.

[Robert Lane]

Slow-downs like what you're experiencing are usually the result of one of 3 things:

1. A system that needs it's directory fixed (use DiskWarrior)
2. A system with old and full cache files and maintenance not done (use Onyx) or;
3. A very long sequence/big project.

Unfortunately one of the things FCP doesn't do very well is refresh/handle it's own cache and internal meta information. It's one of the many things FCP users have been asking Apple to address since FCP 4.

Perform the 2 maintenance taks above and if that doesn't help let us know.

[Eric Emerick]

Thanks for the get-back,

I'm on vacation for the next 10 days out of town, so I'll tackle this when I get back. FYI, I performed a cache flush and I do regular system maintenance. The sequences are not long at all. 3 and 7 minute sequences I'm currently working on. I think I have Disk Warrior around the office somewhere. Thanks.

[Robert Lane]

Actually I totally forgot about one of the biggest reasons why you're experiencing slow-downs, especially if it's gradual: the hard-disk setup.

Bare HDD's were never designed specifically for the ultra-heavy-duty task of video editing, which obviously requires moving around big chunks of data. That also means as you do your work the built-in cache that lives on the HDD fills up quickly (currently the most any drive has is 32MB).

Editing any material whether it's SD or HD will always max-out HDD cache fast; even the 10,000rpm Raptors can't move data fast enough to flush their internal cache completely and so over time - which can often be just a few minutes - things start to slow down while they play a constant game of catch-up.

Whether a drive is in an internal software RAID or externally connected via FW, USB or even eSATA there's no buffer available to the HDD's to offload their cache to and continually refresh. That's why when you see these glossy ads for blazing-fast eSATA RAID speeds it's a bit misleading; the enclosure - regardless who it's made by or how many drives live in it - won't be able to hold that speed as HDD cache fills.

The only way to offset HDD cache becoming full and giving them a place to offload their cache is to have either a SCSI or Fiber external array. The host or controller cards for these setups have their own built-in cache - as do the enclosures they live in - which allows the HDD's to offload their cache and refresh themselves, never filling up and never slowing down the data pipeline.

It's most likely that this is the reason for your slowdowns however I wouldn't be surprised if you see a performance boost initially after running DiskWarrior.