Can someone tell me what the difference is inside the NVR ( looking currently on a DS 7608 NI - E2 ) is between the models with 4 PoE ports and the one with 8 or 16 ?
Is the difference only the amount of ports or any other hardware specs that is better with the bigger models ?
Any 7600 E series NVR are identical hardware-wise. The major difference in hardware is the PoE switch, whether it has 4 or 8 ports. The number after the E indicates the number of SATA interfaces available on the main logic board.
7608NI-E2
76xx = model series
NI = International model (N is the other form of this, lacking the I)
2 = number of SATA interfaces
08 = number of channels supported
Whether 4 or 8, the core hardware is identical, except for PoE ports on the built-in switch. If you look at the inside of one of these, the PoE is not part of the MLB. It's an independent sub-board.
I only got 2 cameras at the moment so works with a 4 port version. but I don not want to get stuck there if I will expand.
I got external standalone PoE so that is no problem for the number of ports.
As long as long-term you have no plans to exceed 4 cameras, that's correct. If you get 8, the same applies but with 8 cameras.
Is there a limit as to how many cameras can be connected to one NVR via the LAN ? I assume the limit surely not is the number of ports but more like 255 or something similar ?
The number of cameras permitted on the NVR's internal subnet (the PoE switch) cannot exceed the number of ports on said switch. If you were to buy an 8CH recorder with a 4-port switch (they are NOT common but you should be aware), you would only be allowed to put 4 cams on the NVR switch, no matter how they are connected physically. The other 4 must tie onto the main network somehow. Silly firmware restriction, but important. Any of the 32CH Hikvisions I install I can only put 16 on the switch because there are 16 ports. I have to have a second PoE switch to handle the other 16, and that switch must be on the main LAN, not the PoE's LAN.
If you want to remote-power all of your cams separate from the NVR with external switches, as long as the total number of cams does not exceed the number of ports on the recorder, that's perfectly fine.
also does it record from the cameras if they record in H.265 which is the one I would like to use
The E series 7600 DOES support H.265 as of the 3.4.0 firmware revision. However, with all that being said, I have H.265 Hikvision camera along with an (allegedly supported) H.265 Hikvision recorder, and for some reason they are grayed out. Have yet to figure it out. The release notes tell all, H.265 is supported on those recorders per Hikvision:
http://www.hikvisioneurope.com/port...ile=NVR_V3.4.0_build150929_Release Notes_.pdf
...and I've never been able to get that protocol to work. I was talking with @
klasipca the other day. He has non-Hikvision H.265 cams with a higher-end NVR than me, and neither of us could figure it out. I am using like-branded equipment. If anyone's setup is going to work, it should be mine. He has mixed brands, couldn't get it to work. I have like-brand, and couldn't get it to work.