Side note. I bought a UCG-max with a 512 m.2 only bc the one without was not in stock. I am not even using it yet. We are doing a new home build and I have pre-bought most of my components.
But I have a 16 channel Lorex NVR with nine 4K PoE camera so I don’t plan to move to ubiquiti for this feature.
That wouldn't all be able to be put on the UCG Max even if you wanted to.
I was going to suggest you could bring that in if you wanted to with the third party camera functionality Unifi Protect has. The problem is the UCG Max can only support a certain number of cameras based on their resolutions. I think with what you mentioned you are already way beyond what it can handle. You could pull some in if you wanted to though.
If a person was thinking many 4k cameras they can look at the unvr for adding disk.
The UDM Pro has one bay. The UDM Pro Max has two. The UNVR has 4 bays and you can use it with UCG. The product page has a wizard for adding drives and number of cameras. It can show you how many days you can get of continuous recording.
I may play around with that eventually. It would be nice to be able to trigger lights on person detection. Right now my Lorex notifies me but I was never able to find and info on an api. A one point I thought I could set a webhook and link it to APImaker but I never figured it out.
For four years I have been simply using an edgerouter 4 so this will be all new to me.
With protect you can create alarm trigger web hooks. So if you have a ptz camera in protect you can use an alarm to have the ptz camera move to a preset. This is extremely useful. So with hubitat you can use sensors to trigger a ptz camera to record the movement using a webhook. You can use fewer cameras and get excellent coverage with ptz. Obviously, you can use other protect cameras with Ai to alert other cameras as well. So someone walking out a door and around a building could be tracked perfectly with a few cameras. Each handing off to the next as the person turned the corner. They are really making some cool stuff.
That is really neat.
OK, weirdness occurred. 
I woke up to a delivery notification from Amazon, and found some clothing (wife's) and an SSD in the packages delivered. I guess I had accidentally put one of the SSDs I was looking at into our cart rather than one of my lists, my wife assumed I wanted it and placed the order.
So I have below...a little accidentally/unintended, but if it's a good choice I can just keep it.
Any concerns w/using this SSD? Will be using it for event recording (not continuous) for max three or four cameras, likely G4/G6 Instants that we'll only have on when we're away from the house on a trip for a week or more so we can peek back into the house if we want to.
I think it will be fine, especially if only recording events.
Personally, I use a 8TB Western Digital Purple HDD in my UDM SE's single 3.5" drive bay. I do record continuously from 5 cameras, so the spinning HDD makes sense.
It’s faster than the gateway will support, but that doesn’t really matter for recording home security cam footage (no one actually needs the speed of flash drives for IP cam recordings).
Looks like the current price on Amazon is as good (or better) than many gen3 PCIe m.2 drives, and that’s pretty much the only downside I could think of (i.e. if you were paying more for speed you can’t use due to the enclosure’s limitation).
As a WD black drive, it should be durable/reliable enough for the task of writing video recordings to disk, although a WD purple 3.5” HDD is an example of a drive that’s built better for such a role.
It will probably be fine, my only concern would be heat. The UCG MAX already runs kind of warm and in my CWWK Mini PC i have 5 NVME drivers, 3 are crucial P3 Plus 4TB drives while the other two are WD drives. The Crucial drives run allot cooler. You will want to watch the temps in the UI for a while if you use that WD drive. Just make sure they don't get crazy hot.
The UI of the UCG Max will also let you know about the wear leveling and how you have impacted the life of the device. I do continous recording on one of my cameras and event recording on the other. After about 9 months or so i am only at 97% life on the drive so it is holding up well. Ofcourse this is the drive that was included in the UCG Max though.
You could also look at the Crucial P3 (non Plus) drive as it is a PCI Gen3
Also for reference if you decide to use the NVR functions Here are the limits
Something else you could consider is that there is also a labs option for "Continuous Archiving". Initially it was a little bit spotty as it would stop after a while but after the last big release it seems to have stabilized.
If you are just doing Event recording it can archive all of the events to a external NAS device for you as well. You may not even need more storage then the smallest option then.
Keep in mind, Event recording and Continuous are not mutually exclusive to. When you setup the camera you specify how you want it to work. You can do either or both and it is on a per camera basis.
Here are the settings on my G4 Doorbell and I have it set to provide both.
That said you can't set different retention for CVR recordings and Event recordings. There is a setting for Enhanced retention that will reduce the retention of High Quality recordings to a shorter time to allow for longer term storage though.
FYI - Not sure if still the case, but when this Enhanced Recording mode was originally released, it broke many 3rd party integrations with UniFi protect, like Scrypted and HomeBridge. Reverting back to the traditional mode allowed these integrations to continue working.
Good to know. I haven't tried it yet as my retention is pretty good right now with just the one camera on CVR
Wow...I had never checked temps on my UCG-Ultra or Max, just checked the UCG-Max and I'm at 75C w/35% CPU load pretty much doing nothing but looking at internet forums. If the SSD is going to jack up temps not sure I should even proceed w/this...
Found a reddit conversation about UCG-Max temps and they told the user:
" Thank you for sharing the screenshot,
Please be informed as checked with our internal team, the UniFi Cloud Gateway Max the max internal temperature of CPU is 115°C.
The UCG-Max Cloud gateway may feel warm to the touch, especially in areas with limited ventilation, but this is normal and expected. The device is designed to operate safely at slightly higher temperatures without damaging internal components or affecting its lifespan.
Curious if anyone else w/a UCG-Ultra or Max is showing temps in this range.
Well mine above is showing 54 degrees for the drive.
Finding the temp for the unit itself is a bit harder as I understand it. You have to log in with SSH and run a command locally on the unit. it is warm to the touch, but there are allot of electronics that are designed to run warmer. The question is where they pulled that temp and what were the ambient temps around it. Mine is in a little electronics cabinet with a AI Port and a Flex 2.5G 8 POE . That switch is also warm since it is powering allot of stuff.
I am not sweeting it, but I certainly wouldn't pick a hot drive to put in it.
You can find a temp for the console here:
Settings>Control Plane>Console>About this console:
Sounds like that is a console temp and maybe not a CPU temp, since they specifically say CPU load for that value in the "About" info.
Appears that after connecting via SSH you can use command below for cpu temp:
'ubnt-systool cputemp'
Ok so there is mine. looks to be hovering around 70-71. CPU seems to be all over the place. I will need to look into that. The latest OS that was just release has some stuff that is pushing the CPU harder.
So if the drive is contributing, it isn't doing much.
I've placed an open-mesh cooking pot trivet below my UCG so that it's up off the shelf (press-board/MDF-type) that it sits on. I had some small silicone feet on it, but figure it can't help to get it up a little higher and have a little more air flow beneath it. 
Just did a few checks of the SSH temp (sudo ubnt-systool cputemp) vs. the Network app UI reported temp, with the Network app temp consistently being the higher of the two by 1.5 to .5 degrees. So the temp from the Network app does seem like the Network app is reporting the console overall temp, and the SSH is reporting the CPU... 
Download the Hubitat app
