7D skipping frames - clarify write speeds

[squidman90]

hey there I have the latest ML nightly build on my 7D

the only module i have installed currently is raw_rec, i disabled the mlv_rec as it skip frames earlier when i recorded RAW video. it only lasted for like 3 seconds then it skipped a frame and stopped.

Is there any quick fix or is there a setting I'm missing?    btw I'm shooting 1728x972

ML allows me to record in RAW (using raw_rec) for like 4 seconds and then does the same thing and goes:

early stop (11) this is a bug please report it

is it my CF card i hope not i just spent $150 on it. Its a SanDisk 64GB 90MB/s Extreme Pro CF.

thanks matt

[Midphase]

Do you have Global Draw on? Also, what is your still photo mode set as?

[squidman90]

yes i have global draw on and its set to "manual" i think that what referring to by photo mode?

[squidman90]

with global draw off I can only get 27.7 MB/s buffer=16384. I purchased a Sandisk Extreme Pro 64Gb 90MB/s speed. do i have a fake card? it should be writing quicker than this.

[Walter Schulz]

Do you have an USB 3.0 card reader connected to an USB 3.0 port? If so you may be use something like CrystalDiskMark or ATTO to verify your results.

[Midphase]

with global draw off I can only get 27.7 MB/s buffer=16384. I purchased a Sandisk Extreme Pro 64Gb 90MB/s speed. do i have a fake card? it should be writing quicker than this.

You should run some benchmark tests within ML to find out what the CF card is actually doing.

Also, I was referring to whether you have the still mode in the Canon Menu set to RAW, JPEG or what. I think you want it set to small jpeg, I think.

[aace]

I have a 7D and I answered a similar question before, that is, if I understand the question. First I'd say identify both the read and write speeds or your cards. I use the Transcend 64GB 1000x cards and I rarely get issues. My 1000x cards max out at (160mb/s read) and (120mb/s write). If you take a look at the chart here: http://www.magiclantern.fm/forum/index.php?topic=6215.0 you'll notice that the 7D maxes out at 80mb/s. The reason I say identify both your read and write speeds is because you mentioned your card in a 64GB 90mb/s. Well what is it 90mb/s at? Read or Write? or is it both.

Also your picture size needs to be set to (jpeg Small). So don't have your camera set to take raw photo (cr2) files. I think it has something to do with the buffer size....

[StefanKeller.AC]

88.8 MB/s with  SanDisk Extreme Pro 32GB 160 MB/s 



http://www.magiclantern.fm/forum/index.php?topic=11617.msg114637#msg114637

[Midphase]

Many people don't seem to realize that the bottleneck in these cameras is not necessarily the card speed but rather the speed of the CF controller chip.

The very same CF card that in my 5D3 writes at over 100mb/sec, when placed in the 5D2 can barely achieve 80mb/sec. This has got nothing to do with the card, and everything to do with the camera.

This is also why we keep seeing incessant new threads about building CF and SD RAID arrays, or CF/SD to USB converters so that we can hook up an external SSD drive to record to. They all miss the basic point that it doesn't matter.

For what it's worth, even the Blackmagic cameras skip frames if the media isn't able to keep up with the write speeds (although in that case, it is a media-related issue).

[OSCA LEE]

Many people don't seem to realize that the bottleneck in these cameras is not necessarily the card speed but rather the speed of the CF controller chip.

The very same CF card that in my 5D3 writes at over 100mb/sec, when placed in the 5D2 can barely achieve 80mb/sec. This has got nothing to do with the card, and everything to do with the camera.

This is also why we keep seeing incessant new threads about building CF and SD RAID arrays, or CF/SD to USB converters so that we can hook up an external SSD drive to record to. They all miss the basic point that it doesn't matter.

For what it's worth, even the Blackmagic cameras skip frames if the media isn't able to keep up with the write speeds (although in that case, it is a media-related issue).

THIS

[aace]

88.8 MB/s with  SanDisk Extreme Pro 32GB 160 MB/s 



http://www.magiclantern.fm/forum/index.php?topic=11617.msg114637#msg114637

So based on your write speeds of your card you should not have any issues. Like a mentioned the 7D maxes out at 80mb/s so the only recommendation I have for you is to disable global draw and make sure you're pictures are set to small. I recall a time trying to shoot raw video and it would pause every 6 seconds or so. I checked everything and everything was good but I still couldn't get to to record continuous until I remembered to set the pictures to small.

[nichilio]

sorry all, i know i'm a newbye and i know u dont like who doesnt read all posts about ML and ask stupid questions BUT.....
i've a 7d, i've disabled global draw, and i've set up SMALL pictures from the canon menu.
i've tried raw_rec and MLV_rec modules, both of em stops after 15/20 seconds.
i'm using a SANDISK EXTREME CF 60 mb/s UDMA 32gb.
Before to buy an 80 mb/s or more i would like if someone of you, much more expert than me says:

YES! YOUR PROBLEM IS THE CF CARD, I'M SURE U NEED A FASTER CF.

thank u very much

[nichilio]

p.s. i'm using a 60x cause i've noticed that while recording canon 7d never gone over 54/55 mb/s

[Frank7D]

Get a faster card and you will be able to record faster/longer (70-80 mb/s is possible).