What hardware are you guys writing to?

Started by Shartnado, March 19, 2017, 11:20:54 PM

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Shartnado

Since shooting RAW footage gobbles up so much data in such a short amount of time, I must ask exactly what hardware are you recording to? I suppose this should be skewed toward users of the t5i like myself, but are you just using multiple SD cards with ML installed on them? I shot about 30 seconds of RAW at my max res (which was only something like 1280x544...it wouldn't shoot higher than that without stopping after about 10 seconds) and that ate up over 1GB of card space. I'm going to be popping that card out in no time, so are you guys just keeping a massive stash of SD cards on hand for shoots? Thanks a lot.

ilia3101

I use a 5D2 with 2 cards, a 32gb Lexar and 128gb Komputerbay, total 160gb of storage, which always lasts long enough for me. I would recommend getting as much space as you can, and make sure the cards are at least Sandisk SD 45MB/s, even better 95. Also as your camera supports 10 and 12 bit raw, try the 10 and 12 bit branch from experimental downloads, recording raw in 10 bit will make the footage take up less space and give you the ability to record in higher resolution. According to the maths your camera could record 10 bit raw at 1728px in 2.35 aspect ratio continuously.

Shartnado

Thanks. I'm using a 32GB Class 10 SD card now. As far as the res goes, I believe my experiments are shooting 14-bit raw. I'll give the 12-bit a try and see how high I can notch the res.

Walter Schulz

"Class 10" designation doesn't tell very much about the card performance.

Modules tab -> Load Bench.mo
Restart cam
Debug tab -> Benchmarks -> Card Benchmarks -> Quick R/W benchmark (1 min)

Shartnado

Ah, I thought it did. I was told to never use less than Class 10, as it met minimum speed requirements. Anyway, my quest to unravel all this RAW stuff continues. Is it possible that the t5i just doesn't take advantage of ML the way other DSLR's do?? Just a thought...

Shartnado

Ok, finally got this test run, and my card results are:

Write speed: 37.8MB/s (1st pass)
                   36.9MB/s (2nd pass)
Read speed: 37.4MB/s (1st pass)
                   37.4MB/s (2nd pass)

Is it time for a faster card???

Shartnado

Ok, I just updated ML to the latest build, hoping it would yield better write speeds, but they're almost exactly the same as before. I'm very curious about this 10 and 12-bit raw recording to see if I can up the write speed, but the "Experiments" page isn't very clear about which file I need for my camera. Can someone advise? Thanks.

Shartnado

Guys, please disregard my last. The models are hidden in plain sight right in the zip filenames, sorry. Thanks.

Shartnado

Ok, I loaded the 10-12 bit ML experiment, but sadly it did nothing to increase write speeds. Is there a setting somewhere that needs to be engaged first? Sorry to hog this thread.

Walter Schulz

10/12-bit is not about increasing write speeds but decreasing bandwidth needed for given resolution and frame rate.
10 vs 14 = about 72 percent.
12 vs 14 = about 86 percent.

Shartnado

Of course, this makes sense. In some strange way, I think this is what I was attempting to say (I know, liar liar...) Anyway, I ran a test raw recording of about a minute, and the max settings I was able to record uninterrupted was something like 1600x800 with an aspect ratio of 2.5:1. I need to get back later and do more of these and jot down my results so I can zero in on the best choice.

This SD card claims to do 90MB/s, but I'm clearly not even sniffing that. Is the card the issue, or is my camera just topping out at 37MB/s do you think?

Walter Schulz

SD-card interface in your cam is SDR50/DDR50 = 47.68 MB/s. Because of overhead you will get about 41 MByte/s in benchmarks for write in photo mode with fastest cards. And because of additional overhead (unavoidable) you will not get this number in real life = recording.
To verify card's real performance margins you will need a decent USB 3.0 cardreader (or anything else not bandwidth limiting) and a benchmark tool (CrystalDiskMark for Windows). Most card manufacturers just print card's read performance on label. See http://www.cameramemoryspeed.com for benchmark numbers and difference between write and read for various cards.

pocketrubbish

Yeah when I would shoot on my 6D I would have a few cards all with ML installed. Now with the 5D its a bit easier, leave the SD card in the cam with ML and then swap out the CF cards. I have 4 64gb CF cards and always keep a laptop close by while shooting so I can offload the footage and back up as I go, constantly rotating the cards. 64 gigs fill up in a bit over 15 minutes but I figure this is how it was done with film reels and it's certainly worth the extra effort.

In fact it makes me a better shooter in the same way shooting with film does. Having that limit makes you think about the framing and exposure more versus shooting willy nilly. I don't hit that record button until I'm absolutely ready.