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Drive compatibility with Atem Extreme Iso

PostPosted: Wed Jun 02, 2021 3:51 pm
by Streamium
Hi everyone,
I just bought the Atem Extreme ISO and looking for some SSD drive advice.

I am interested in using the Samsung T5 or T7 drives. I heard the T7 is significantly faster than T5, but people had issues with it in 2020 on the original ISO. Have these now been resolved and is it reliable?

Is the T5 capable of recording 9 feeds, in terms of speed?

Approximately how much recording time would I get from 500Gb drives?

Is there any advantage in having 2 x 500Gb drives over 1 x 1TB drive? Could a USB-C hub be used to achieve this?

Is it true the drive needs to be formatted as ex-FAT to work properly?

I'm steering towards the T5 as this never seemed to have compatibility issues. But as the T7 is reasonably priced, I would prefer a drive that has substantial speed capability with all streams recording (this is an edge case though). Reliability is key though. If the T5 is both reliable and ample for long recordings of 9 streams, I'll just go with that.

Thanks for any help


Re: Drive compatibility with Atem Extreme Iso

PostPosted: Sat Jun 12, 2021 7:07 pm
by Streamium
I have answered my own questions. So posting what I found in case it helps others.

The issues people had with the T7, were from 2020, and with all the hardware updates, and the latest T7 drives, these issues seem to be resolved.

I've successfully run tests today and had 4 streams of video plus the program feed, all spooling to the disk. I haven't tried with additional inputs but confident there wouldn't be an issue. I also used BM's speed test tool on the disk and via USB-C, was getting near to the manufacturer's quoted speeds (over 800MB/s read and write consistently).

In terms of disk size, I ran a crude and not very scientific test. I came to the conclusion that with 4 feeds and programme, I'd get around 300 minutes of recording. Data and assumptions below

The entire ISO folder was 9.2GB for a recording lasting 6m20s. The program file was around 220 Mb which is tiny. However each of the camera feeds was a bit bigger at around 2.2Gb. Channels which had no input were a few MB.

In addition was a single media pool image that was used, but trivial in size.

So in my tests, about 1.5 GB per minute. A 500 GB disk would last just over 300 minutes. But this was just 4 channels with any content. As the camera feeds take up a vast majority of the space, I would estimate 8 active feeds would take 3GB per minute approx. Meaning the same paltry size disk would still deliver 150 minutes which is over 2 hours! This is most impressive

What I found a little interesting is that the ISO recordings for each camera, seem to use a massive amount more space than the program feed. I'd read that the recordings are as compressed as the quality of the stream feed. But wondering if this doesn't apply to the ISO feeds. For example my program video was 220MB vs over 2GB for one of the video channels. So it's nearly 10 times as much.

I'm actually quite pleased about this if it's true. If file size is synonymous with quality, then I could recut the stream in higher quality after the event, or utilise camera clip for a showreel, without worrying the the stream quality happened to be poor on a particular day.

Hope the above is useful to someone. I'm certainly relieved I seemed to have worked it out now.

Re: Drive compatibility with Atem Extreme Iso

PostPosted: Tue Jun 22, 2021 1:16 am
by Tim_Partridge
Blackmagic have published this list of drives relatively recently:

Other posters have suggested that the recording is 70 megabits per second per video channel. (Divide by 8 to get megabytes)



Re: Drive compatibility with Atem Extreme Iso

PostPosted: Tue Jun 22, 2021 8:15 am
by Streamium
Wow Tim thanks so much. This is just the info I was looking for. Very helpful in forward planning disk space needed.