FCP X Choppy playback

Question

brock29692 Author

Level 1

6 points

FCP X Choppy playback

Setup:

iMac Retina 4k 2017

3.6 i7

32GB memory

Radeon Pro 560 4096 MB

Hard drives with video:

Blackmagic Thunderbolt 4 disc SSD drivebay with SanDisk Extreme PRO SSDs recorded on Blackmajic Hyperdecks

Apple thunderbolt Cable with an apple thunderbolt to USB C adapter

The performance is set to Better Performance, the video files (Recorded at ProRes 422 HQ 1280x720 59fps) and the project settings match.

The issue is worse with Multicam (4 cameras) than with single footage but its there when playing back one channel.

Any ideas what might be causing this?

Thanks everyone

iMac, macOS High Sierra (10.13.6)

Posted on Nov 2, 2018 7:15 AM

Reply

Answer 1

W. Raider

Level 3

797 points

Nov 2, 2018 8:07 AM in response to brock29692

That's weird behavior. My first thought is disk speed. You can try black magic's speed test tool

https://itunes.apple.com/us/app/blackmagic-disk-speed-test/id425264550

And see what it reports.

Other thoughts are if you updated to Mojave Spotlight could be indexing those drives. You can tell spotlight to ignore them in system prefs.

Reply

Answer 2

brock29692 Author

Level 1

6 points

Nov 5, 2018 7:35 PM in response to Alchroma

Actually, the files play fine when only one drive is inserted, just not when all 4 are inserted. It seems to be getting the drives confused in HFS. It didn't do that in ExFat. I tried naming each HFS Drive HFS1, HFS2 etc. That seemed to let every file play but its not playing the actual files its just playing drive one files still.

Reply

Answer 3

brock29692 Author

Level 1

6 points

Nov 12, 2018 12:59 PM in response to Alchroma

Ok. So I have talked with blackmagic and apple. There’s no way to configure the drives in any way other than what I have done (ExFat or HFS+) I don’t believe. Apparently neither blackmagic format is ideal for newer apple OSs. And there is no indication anywhere that that is going to change. HFS+ isn’t really supported by apple anymore, and apple says there are issues with HFS+ and High Sierra and higher. So I’m stuck with ExFat I guess. I guess I may have to deal with the choppy playback?

Reply

Answer 4

Alchroma

Level 7

23,912 points

Nov 2, 2018 6:10 PM in response to brock29692

How are your SSD drives formatted?

Your system should blow away that sort of footage without even getting a sweat.

Can you also tell us the specs of the video and audio can use please?

Al

Reply

Answer 5

Alchroma

Level 7

23,912 points

Nov 6, 2018 12:14 AM in response to brock29692

I believe the software will allow the drives to be configured differently. eg RAID or single.

This would affect how replay.

Consult the manual.

Al

Reply

Answer 6

brock29692 Author

Level 1

6 points

Nov 3, 2018 10:00 AM in response to Alchroma

Drives are formatted in ExFat but I’ve tried HFS and things seemed worse. Although I’ve had multiple little issues so I’m not sure if the HFS was as bad on playback. I could try it again.

Video is recorded at 1280x720 to prores422 HQ I believe. 48k audio I think via 2 XLR on the pro unit. Not 100%. At home today but I think that’s correct.

Reply

Answer 7

brock29692 Author

Level 1

6 points

Nov 5, 2018 7:25 PM in response to Alchroma

I just remembered why I went back to ExFat from HFS+. I can't open the majority of the files in HFS+. Some of the files say I don't have permission. When I click info, there is a lock at the bottom right. The permissions are set to Read and Write but I can't open the file. I tried to unlock and apply enclosed items. Either the files on each disc continue not to play or they play the wrong file. It seems to want to play a file that actually exists on another drive. I thought maybe it was a naming convention issues as each disc was originally titled Capture0001, Capture0002 etc by the hyperdrives. I changed the names but that doesn't seem to help. Any ideas?

Reply