Great video shows why loud noises make drives drop frames

[Brent J. Craig]

Brendan Gregg, a researcher at Sun has proven quite conclusively that his hard drives experience more latency (slow down) if he yells at them. Check out his blog entry and be sure to watch the video clip. (http://blogs.sun.com/brendan/entry/unusual_disk_latency)

I will try to translate some of the nerd-speak: Gregg talks about "J-BODs" which is a type of RAID system configured as "Just a Bunch Of Disks".

This has obvious implications for Red users as many have experienced dropped frames and IO errors when shooting with the Red Drive in loud environments. I think it is important for us to realize just how delicate spinning hard drives are how our footage can be affected by simple things like loud noises.

[Jonathan Stevenson]

Dang, that's nuts!!

I guess the CF cards or the new Red Mags wouldn't experience this...

[Michael Morlan]

Yep, I had a woman's scream in a small bathroom cause my REDDrive to drop 80 frames. Another thread here also revealed dropped frames from squealing tires in parking garages, bass/percussion on a music video, and even an A.C.'s fart.

http://www.reduser.net/forum/showthread.php?t=15851

Michael

[Patrick Tresch]

... and even an A.C.'s fart.



Very concerning!
This is an issue RED has to tackle!!!:biggrin:

[Steve Sherrick]

For what it's worth, with ET's shock mount, I shot a techno/hip hop nightclub event and dropped zero frames using the RED drive. I'm sure you can imagine there was some serious bass, and loud enough to make me wear earplugs.

[Brent J. Craig]

For what it's worth, with ET's shock mount, I shot a techno/hip hop nightclub event and dropped zero frames using the RED drive.

While shockmounts seem to help, I don't think anything will prevent the platters in a drive from occasionally being hit by their perfect resonant frequency. I would never use a drive to shoot loud music.

[Steve Sherrick]

While shockmounts seem to help, I don't think anything will prevent the platters in a drive from occasionally being hit by their perfect resonant frequency. I would never use a drive to shoot loud music.

I agree, but this was a test for me to see how far I could push the new mount and it worked without issue. Not only was the music loud, but I was handheld bouncing the camera around. For live concerts, club shows, etc. CF cards are not that useful. Too many offloads, downtime. Until the RED solid state drive drive shows up, the compromise is to shoot with the Red Drive with an ET mount. For some this may be too risky, and I understand that. In which case, perhaps going with a different camera/format will be best choice.

[Matthew Rogers]

I just shot a country music concert recently, handheld, with the RED drive and no dropped frames. Neither did the other handheld camera in front of the speakers. The RED's on the dolly and jib didn't have issues either. I wonder why sometimes it happens and sometimes it doesn't...

Matthew

[Gregory Sheffer]

Try shooting airplanes out on the tarmac. I learn all this the hard way.

[Steve Sherrick]

Try shooting airplanes out on the tarmac. I learn all this the hard way.

Airplanes may be a challenge. I know Stephen was doing some testing to see if the mount worked well in aerial situations. Maybe he can comment on those tests. But, back to the music, I was shooting an event without the ET mount early on and almost immediately got dropped frames as soon as the bassy music kicked in. So, the ET mount clearly has improved the vibration problems that cause the drive to drop frames.

But do test in any situation where you feel vibration can be an issue and let this guide you as to what format to work with. If you have been hired to shoot a Rolling Stones concert using several Red cameras and the margin of error is zero, which of course it would be in the case of a superstar rock band, then do tests, have backups available for the show, do whatever is within your power to make sure you don't walk away with dropped frames. I suppose another option is to go with 16GB CF cards, and coordinate offloads so they are staggered enough that a camera is only down momentarily. But I can't imagine this is going to make the director/producers happy. No one wants a camera down at any time. But currently, this is probably the safest option until the SSD arrive.

[Vinit Borrison]

No wonder i can't record any footage while my mother is around!!!!! It finally makes so much sense to me. hahah thanks brent =)

[Jason Osterday]

Just did a western with plenty of guns and no drops. RED drive with standard mount.