Questions About Continuous Recording

[diver165]

I have a Blue Iris system running on a Dell PC. I currently have 500gb internal SSD and a 4tb SATA HD. I have 20 cameras (primarily 4 and 5 mb Dahua). I'm using motion triggers to capture events. But I would like to go continuous. I realize I have a pretty large pool of cameras. I looked at the page (on this forum) to calculate storage needed. I'm guestimating a needed space of about 9 terabyte.

Questions:
1. Can I have mixed recordings. Example, some cameras would capture continuous while others capture on motion. I don't need continuous recording on about 5 or 6 of my cameras.
2. Can you use an external HDD w/ USB 3.0 as a primary HDD for continuous recording on Blue Iris?

Right now WD Purple survellance rated HD is about 250 for a 12tb drive. I can go internal HD, that's not a problem. But I was just thinking of the ease of plug and play with an external HD setup

 

[looney2ns]

1-Yes, absolutely.
2-Bad idea, folks have found that the USB stream can't keep up with the continuous data camera's send.

 

[diver165]

1-Yes, absolutely.
2-Bad idea, folks have found that the USB stream can't keep up with the continuous data camera's send.

That's why I was thinking USB 3.0 which "should" be like 6Gbs

 

[Ri22o]

Mine are a hybrid of motion and continuous. Most of mine are continuous during the day because even if motion doesn't cause it to switch to main stream I can still have an idea of things that happened at distance. And then at night I have some switch over and record continuous so I can make sure and not miss anything.

This does mean I get less length of time in the winter because night is longer, but it's still a reasonable enough amount of time to go back and look.

 

[looney2ns]

That's why I was thinking USB 3.0 which "should" be like 6Gbs

Well, you've been warned.

 

[wittaj]

That's why I was thinking USB 3.0 which "should" be like 6Gbs

The theoretical transfer speed of USB 3.0 is 4.8 Gbit/s (600MBps) and when I tested it with 2 cameras for the live recording, it started stalling after 25min. It can't keep up with the sustained, non-buffering of video cameras.

Theoretical and real-world and sustained are totally different numbers.

It can even struggle with moving already recorded video over.

So here is a real-world demonstration. I was trying to move roughly 260GB of data from NEW to STORED.

I was moving it from a WD Purple (750 MBps) through a USB 3.0 (625MBps) port to another WD Purple HDD (750MBps)

At first it said it would take about 2 hours to move 260GB, but look how fast it dropped to a transfer of 37.7MB/s

Two hours came and went. About 6 hours later, the speed had dropped to less than 2 MB/s.

260 GB (260,000 MB) should have taken 416 seconds or less than 7 minutes at the theoretical speeds.

Those speeds just are not going to cut it for live recording of non buffering video.

Some say they work just fine, but I suspect they simply haven't had an incident happen yet where they found out they are missing recordings.

 

[diver165]

The theoretical transfer speed of USB 3.0 is 4.8 Gbit/s (600MBps) and when I tested it with 2 cameras for the live recording, it started stalling after 25min. It can't keep up with the sustained, non-buffering of video cameras.

Theoretical and real-world and sustained are totally different numbers.

It can even struggle with moving already recorded video over.

So here is a real-world demonstration. I was trying to move roughly 260GB of data from NEW to STORED.

I was moving it from a WD Purple (750 MBps) through a USB 3.0 (625MBps) port to another WD Purple HDD (750MBps)

At first it said it would take about 2 hours to move 260GB, but look how fast it dropped to a transfer of 37.7MB/s

Two hours came and went. About 6 hours later, the speed had dropped to less than 2 MB/s.

260 GB (260,000 MB) should have taken 416 seconds or less than 7 minutes at the theoretical speeds.

Those speeds just are not going to cut it for live recording of non buffering video.

Some say they work just fine, but I suspect they simply haven't had an incident happen yet where they found out they are missing recordings.

OK! My 20 camera system would trash it if I continuously recorded all 20 cams LOL

So when I switch to continuous which mode should I choose? Continuous, Continuous + triggered, Continuous + alerts? I also use deep stack btw.

 

[wittaj]

That is up to you.

Continuous will record the mainstream 24/7

Continuous + triggered will record the substream until triggered, then mainstream, then back to substream.

Continuous + alerts will record the substream until confirmed alert from Deepstack, then mainstream, then back to substream.

Most here will do Cont+triggered - that way you get 24/7 recording of mostly substream and saves on storage space.

Most do not record cont+alerts because deepstack could go down or not recognize and then you don't get mainstream of the triggered event.

 

[diver165]

Most here will do Cont+triggered - that way you get 24/7 recording of mostly substream and saves on storage space.

Most do not record cont+alerts because deepstack could go down or not recognize and then you don't get mainstream of the triggered event.

That's what I want to hear. I use subs. Now....I have a couple cameras I don't need 24/7 recording. Can those individual cameras still do triggered?

Thanks for your help so far btw

 

[wittaj]

Yes you can do triggered or cont on any camera. It is camera specific how it is set up.

 

[Photon Farmer]

2-Bad idea, folks have found that the USB stream can't keep up with the continuous data camera's send.

I find all the different USB flavors confusing.
2
3
3.1
4
Gen1
Gen2
I currently have seven cameras going continuous capture to a USB 3.1 Gen2 raid.
About two years ago I had around fourteen to sixteen cameras all going continuous capture to that raid.
Even while playing back video with all those cameras going continuous capture the USB 3.1 Gen2 raid kept up.

I am not saying all versions of USB are fast, yet at least one version seems decently fast to me.