CF card speed can not reach full potential Write Speed

[erickliu]

I just went out and bought some very high end CF and SD card.

-Sandisk Extreme Pro 32gb 160Mb/s CF Card
-Sandisk Extreme Pro 64gb 280Mb/s SD Card

The problem is, when I try to record into CF just at 1080 in Raw, I get skipped frames around 13 seconds in.
I run a benchmark and the average write speed for the card is around 80Mb/s, while the card itself is certified to  have a Write speed up to 150Mb/s

I have ML firmware 1.2.3 and have file_man, mlv_play, and raw_rec enabled

[DeafEyeJedi]

Did you try BM'ing it in 24fps (w Global Draw off) and again in PLAYBACK mode 24fps (w Global Draw OFF)?

If not, please do so...

Results?

If still unsure about your cards' performances... read this link.

http://www.magiclantern.fm/forum/index.php?topic=12630.msg121741#msg121741

p.s. don't forget that the 5D3 SD's slot bottlenecks it at about *40 mb's (regardless how fast the SD card can be) whereas the CF slot can achieve up to about 120 mb's depending on your cards write speed. (I can push it up to 106 mb's in 3x crop mode 2.5k with KB 128gb 1066x)

**edit**
I was incorrect on this due to throwing it off top of my head and the correct info is 21 mb's!

[walter_schulz]

Sandisk Extreme Pro 64gb 280Mb/s SD Card:
UHS-II is not supported by any cam currently able to run ML. If used in UHS-I mode write performance is about 45 MByte/s. SD-card interface in 5D3 is limited to about 21 MByte/s write. DeafEyeJedi got it wrong here.
BTW: You might mention the cam type you're using when asking for help.

Sandisk Extreme Pro 32gb 160Mb/s CF Card:
What does "average" mean? Arithmetic, geometric, harmonic?
It's maximum write speed that matters. Benchmark will write a file BENCHx.PPM which can be transformed to JPG. Upload it somewhere (Picload or else) and link it here.
Use movie mode + Global Draw off + no module loaded.

[DeafEyeJedi]

My fault on that guys -- I was just throwing off the numbers that I had remembered in my head and I checked throughly through google and it is in fact up to 21 mb's so yes I was, in fact, incorrect.

Good catch @walter_schulz and my apologies for the confusion @erickliu!

[erickliu]

Sorry about that guys, I'm using a 5D Mark III and am shooting to achieve usable 4K footage on it. I did see some articles talking about that if you have a SD card in at all, it will bottle neck the CF card. Is this true?

[erickliu]

@walter_schulz what type of benchmark do I run? And where will the file be saved

[walter_schulz]

Debug tab -> Benchmarks -> Card R/W benchmark (5 min)
Location is card's root directory.

[erickliu]

Ok let me do that

[erickliu]

Ok

[erickliu]

@walter_schulz

[erickliu]

http://imgur.com/CBRCoAj

[walter_schulz]

I wrote: Global Draw OFF. Redo, please.
And you are allowed to edit your posts instead of creating several with no content.

Numbers do look quite plausible.
http://www.magiclantern.fm/forum/index.php?topic=12630.50
To run Playback mode you have to start the benchmark and press PLAY button. Fast.

[erickliu]

http://imgur.com/a1N19gi

[DeafEyeJedi]

Looks like a decent card -- did you try in 24fps?

You may be able to achieve slightly faster write speeds in 1.1.3 as I've confirm this in previous tests w myself.

[erickliu]

How much faster and yes I've tried 24fps but I'm looking to shoot for 4k or at least 2k

[walter_schulz]

Numbers are just what to be expected in this mode.
You will find DeafEyeJedi's quite extensive benchmark session in the link I posted above.

And you won't get continuous 4k regardless which card you may use.
Math section
Data rate (Byte/s) = vertical resolution * horizontal resolution * fps * 14/8
Data rate (MByte/s = number above /(1024 * 1024)
This is the number ML is telling you for each resolution/fps combination you select.