Please help me underderstand these specs:

[Perimeter]

It is about the Dahua NVR2108HS-I2, but applies to all really:
It has 8 channels.
The specs state for decoding capability:

AI disabled: 1-channel 12MP@30 fps; 1-channel 8MP@30 fps; 2-channel 5MP@30 fps; 3-channel 4MP@30 fps; 6-channel 1080p@30 fps
AI enabled: 1-channel 8MP@30 fps; 1-channel 5MP@30 fps; 2-channel 4MP@30 fps; 4-channel 1080p@30 fps

I assume the semicolon stands for "OR"?
So if I use 4MP cameras with the NVR-AI disabled, I could connect 3 of them at 30 fps. Does this mean I could also connect like 6 cams at 4MP@15 FPS? Or 8 cams at 4MP@10FPS? Or is it 3 cams with 4 MP and that was it?

And do I have to enable AI for all or none or can I enable it for some cams and not for others, in order to save performance.

 

[garycrist]

Put the AI in the cams if they are "smart" enough.

 

[Perimeter]

Well yes, but if I let it run without AI, what can I connect? Can I connect more cams if I lower their frame rate?

 

[wittaj]

If the camera has AI, then you don't need to use the AI in the NVR. That feature in the NVR is for a camera without AI.

Yes, no reason to run a camera at 30FPS, so running at 10FPS or 15FPS will help. But you will probably need to drop bitrate and resolution to run 6 or 8 cameras on this.

BUT, as I mentioned to you in your other thread, not all NVRs are equal and you have to be careful of the decoding and bandwidth.

This is a budget NVR and will get crippled pretty easily.

No point in having the 4MP 5442 camera if the NVR cannot support the number of cameras you have.

The bandwidth of this NVR is 80 Mbps for access, 80 Mbps for storage and 60 Mbps for forwarding. Depending on how you set up your cameras, you may only get to run 4 or 5 cameras.

We see people here all the time with an 80Mbps NVR and have 4 cameras and add a 5th and nothing. They then need to downrez the cameras in order to run all 5 cameras. Downrezing makes no sense and while cripple the capability of a camera.

 

[alastairstevenson]

So if I use 4MP cameras with the NVR-AI disabled, I could connect 3 of them at 30 fps. Does this mean I could also connect like 6 cams at 4MP@15 FPS? Or 8 cams at 4MP@10FPS? Or is it 3 cams with 4 MP and that was it?

The decoding specs are for viewing multiple streams, which need to be decoded to render the video, as opposed to the number of channels that are available to record from.

 

[Perimeter]

The bandwidth of this NVR is 80 Mbps for access, 80 Mbps for storage and 60 Mbps for forwarding. Depending on how you set up your cameras, you may only get to run 4 or 5 cameras.

When I ran that 5442, the web interface shows me that I max at ~8000 kbps (which I set as limit in the camera). Now that is ~8 Mbps. So I figured 80 Mbps should be plenty for 8 channels. Where is my mistake?

 

[wittaj]

All I can say is people's experience says otherwise.

That 8Mbps is that video stream and doesn't account for the bandwidth needed to send the triggers, substream, etc.

Buy it from a place that has free returns so when you hook up at 8 cameras and it is all glitchy or can't show them all you can return it...

 

[wittaj]

Here are a few recent threads where people hit that 80Mbps quickly...

Dahua NVR only recording and allowing to view 4 cameras out of 6

Hi all, have been running a BI system for a number of years with no dramas. I decided to try out a Dahua NVR for a new remote storage location we have, I fear I may have purchased an NVR not up to the challenge or I am just being a noob which would be the better outcome. The model is Dahua...

ipcamtalk.com

Max Throughput Spec for Amcrest AMDV8M8-HD DVR

Trying to sort out the max payload options for the DVR above using a variety of 2MP analog cameras set up to their maximum capabilities and hoping to add at least a pair of IP 5s as well. Doesn't seem like it should be a problem, but... I see mention of an 80Mbps ceiling on some of the...

ipcamtalk.com

flux main stream

hello to all and sorry for my English I'm taking a translator, I have a little problem, I have 4 Dahua cameras installed and I'm connected in hdmi to a 43-inch tv, on the 4 cameras I can see 2 sound cams on the M stream, that is to say the main stream, but the other 2 are on S2 secondary stream...

ipcamtalk.com

Recording and live view glitching

Hi all Can anyone explain why this is occurring randomly and semi-regularly on two different cameras? Cameras are DS-2CD2387G2-LSU/SL into NVR DS-7608NXI-I2 / 8P/S. Thanking you in advance.

ipcamtalk.com

NVR crashing when accessing through webpage.

I have a Hikvision DS-7604NI-E1. I've just today updated one of my cameras so need to access NVR through webpage to fine tune. I can get onto the webpage and access Local - System - Network - Video/Audio - Storage - Vehicle Detection and VCA no problems. When I click on either Image or Event...

ipcamtalk.com

 

[wittaj]

I know costing is different where you live based on other members posts, but in the US, this NVR sells for around $150ish USD.

We can buy an 8th gen refurbished computer for that or less and then run BI and not be limited by the same bandwidth restrictions of an NVR.

 

[Perimeter]

I appreciate the posts, kind of interesting how much can go wrong when people don't double/cross check issues.

I know costing is different where you live based on other members posts, but in the US, this NVR sells for around $150ish USD.

We can buy an 8th gen refurbished computer for that or less and then run BI and not be limited by the same bandwidth restrictions of an NVR.

I could get it through Amazon for about the same. But it isn't a matter of cost but of time really. I do have an 8th generation intel standing here, BI-eval is installed. But I will take time to figure it out.
By the way, is it known which of these NVRs don't have fans? I googled some pics and it seems this one doesn't have one.

I checked for NVR5216-4K-S2, which would be more than twice as expensive. And Dahuas spec sheet says EOL to the entire 5xxx series.
The only confusing thing: Amazon themselves sell this model for two different prices. One has the prefix "Dahua Europe Pro", the other just Dahua. I just fear they will be noisy.

I have already concluded that I'd rather go the path of using seperate PoE injector switches so that I can switch to or perhaps even add BI at a later time with little new investment. It also occured to me that it might be easier to set up the second POE switch in the annex instead of running several POE cables there. I could just run one regular cable or use a powerline adapter to connect. Just a question of how much bandwidth I get through the powerline. My test with one cam set at max bitrate seemed to work fine. The powerline app reports over 100Mbit as available transmission rate.

After searching a little more on Dahua's website, I found NVR4208-4KS2/L. It lists 160 Mbps while the NVR4108-4KS2/L lists 80Mbps.

Edit: I have to thank you again. Due to your input, I stumbled upon a 4208 at amazon warehouse for less than the 2108 would be new. I'll give that one a spin. If I don't like it, I'll send it back.

 

[Perimeter]

Update:
It did actually work out: I got a Dahua NVR4208-4KS2/L for $100 +VAT from Amazon warehouse. Seems like a nice deal to me so far. I can find out if I prefer an NVR or BI without having to rush it or get overly invested.

What I now need to understand is the interoperability of NVR, web interface and smartPSS. I learned how the use the SD card with smartPSS. So far, I found no way to tell the cam how to go about the SD card from the recorder. Is that not an option?

 

[xlarons]

Update:
It did actually work out: I got a Dahua NVR4208-4KS2/L for $100 +VAT from Amazon warehouse. Seems like a nice deal to me so far. I can find out if I prefer an NVR or BI without having to rush it or get overly invested.

Hi again, how are you getting on with your 4208? Have you decided to stick with it or try BI or Scrypted? My shiny Dahuas are going to waste whilst I dither about which NVR to buy!

 

[Perimeter]

Hi again, how are you getting on with your 4208? Have you decided to stick with it or try BI or Scrypted? My shiny Dahuas are going to waste whilst I dither about which NVR to buy!

Hi,
after having played with it, exchanged the fan, I started using it. I did write a note on some things, which I linked for you in the other thread.
So far (3 cams) I am still happy with it. I added a Dahua POE switch to power the cams, all is working well at the moment. I'd buy it again for that money. Just take note that I don't do this for a hobby, so I don't plan to spend much time with it while it is running.
As the number of cams will be rising, I may still find it to be inadequate at some later point. But as it was $100, that would be acceptable.

 

[xlarons]

Hi,
after having played with it, exchanged the fan, I started using it. I did write a note on some things, which I linked for you in the other thread.
So far (3 cams) I am still happy with it. I added a Dahua POE switch to power the cams, all is working well at the moment. I'd buy it again for that money. Just take note that I don't do this for a hobby, so I don't plan to spend much time with it while it is running.
As the number of cams will be rising, I may still find it to be inadequate at some later point. But as it was $100, that would be acceptable.

Thanks...great update and I'm glad you're pleased with it. I am so pleased you highlighted the bandwidth issue. I cannot fathom what makes this issue though, i.e. the CPU in the NVR, the bandwidth from the CPU to the hard drive, the network interface, it's strange.

I am torn between a fancy Dahua and buying a PC to test out Scrypted and / or Blue Iris and feel a dedicated PC would surely not suffer any bandwidth issues.

 

[Perimeter]

I am so pleased you highlighted the bandwidth issue.

Actually wittaj did that.

I cannot fathom what makes this issue though, i.e. the CPU in the NVR, the bandwidth from the CPU to the hard drive, the network interface, it's strange.

I know nothing about it really. But in this big NVR there is just a little piece of hardware the size of a box of cigarrettes. I would not be surprised if there is little difference in hardware. All differences within a series might just be created by soldering or firmware. Similar to CPUs.

I am torn between a fancy Dahua and buying a PC to test out Scrypted and / or Blue Iris and feel a dedicated PC would surely not suffer any bandwidth issues.

Same here. Making a decision that requires knowledge and experience without either sucks. A dedicated PC is going to consume quite a bit more energy 24/7 than an NVR. I even have a suitable PC here. I watched some videos and found that an NVR interface works similar to a cam interface. I don't plan to check it every day, I am not a store owner. I wanted 24/7 recording stored away from the cameras.

So I figured that I need to gain experience and knowledge in order to decide the issue. I would have to accept making the wrong choice. When I found the 4208 in amazon warehouse, I bought it. Minimal risk investment due to 30 days return. Never seen cheaper. Plenty of time to figure out if it does the trick. From specs, it should be good enough. And most important: Minimal time investment as it is as ready for Dahua as possible. I had to figure out what AI actually meant, but that turned out to be exactly what I wanted.

If I ever need more recording than this thing can offer, I can decide if I get a bigger recorder or a BI-PC. Based on knowledge and experience.

 

[fenderman]

Actually wittaj did that.


I know nothing about it really. But in this big NVR there is just a little piece of hardware the size of a box of cigarrettes. I would not be surprised if there is little difference in hardware. All differences within a series might just be created by soldering or firmware. Similar to CPUs.


Same here. Making a decision that requires knowledge and experience without either sucks. A dedicated PC is going to consume quite a bit more energy 24/7 than an NVR. I even have a suitable PC here. I watched some videos and found that an NVR interface works similar to a cam interface. I don't plan to check it every day, I am not a store owner. I wanted 24/7 recording stored away from the cameras.

So I figured that I need to gain experience and knowledge in order to decide the issue. I would have to accept making the wrong choice. When I found the 4208 in amazon warehouse, I bought it. Minimal risk investment due to 30 days return. Never seen cheaper. Plenty of time to figure out if it does the trick. From specs, it should be good enough. And most important: Minimal time investment as it is as ready for Dahua as possible. I had to figure out what AI actually meant, but that turned out to be exactly what I wanted.

If I ever need more recording than this thing can offer, I can decide if I get a bigger recorder or a BI-PC. Based on knowledge and experience.

Have you checked the power consumption on a modern PC? They pull under 15 watts at idle and 50 or 80w under full 100 percent load. Power consumption should not be a consideration.
I do suggest that everyone start out with an NVR this way they can see how shitty they are and when they upgrade to a PC-based VMS which can do what they like they will appreciate it more...