[SOLVED] NVR configuration help

[mlitos]

I am building a video NVR and initially was going to connect my 6x HDDs (12TB WD Purple) through the onboard MB SATA connectors for video storage. This would max out the capacity of the board and force me to use a specific M.2 slot (for an NVMe SSD OS drive) that didn't share bandwidth with the SATA ports which isn't an issue. I'm rethinking my build and ordered a 16 port PCIe 3.0 x8 add in RAID card to support expandability or a 2nd RAID array. My MB has 3x x16 physical slots that are (x16/8/4) electrical. I will be using the CPU's built in graphics and an NVIDIA graphics card to support the NVR software's analytics capability. The NVR will function strictly as a server and not a server/client so the CPU graphics capability is adequate. My current NVR shows less than 10% analytics load and I am not expanding the number of cameras, etc. in moving to the new NVR so dont anticipate the analytics load to be any higher. The MB is the Gigabyte Z490 Vision D. The first 2 PCI Express slots are controlled by the CPU and the 3rd PCI express slot is controlled by the Z490 chipset.

So with that background out of the way and with the understanding that I will have a graphics card in the first x16 slot should I:
A) connect the RAID adapter card in the 2nd x16 slot and force the graphics adapter to run x8 but allow the RAID adapter to operate at it full rated x8 speed or
B) connect the RAID adapter card in the 3rd x16 physical/x4 electrical slot, allow the graphics adapter to run at x16 but reduce the RAID adapter to half its capable bandwidth at x4

I am leaning toward putting the RAID adapter in the 2nd slot unless there is no way that up to 16x SATA 3 HDDs can saturate the x4 electrical interface the RAID card would be connected to.

Thanks in advance for your recommendations and your expertise.

-M

 

[mlitos]

So I'm researching this a bit more. Looking at actual performance of the WD purple drives at https://hdd.userbenchmark.com/ is see the the 8TB (no listing for the 12TB but both are 7200RPM) shows ~150MB/s read and write performance (~75MB/s mixed). Worse case at 150MB/s x 16 drives it would be 2.4GB/s. Looking at a few resources I see 3.0 x4 PCIe slot has a theoretical max of 3940MB/s so enough to support 16 drives pushing max read or write speeds even considering overhead.
The other thing I'm thinking about is the IP cameras as currently configured result in incoming bandwidth to the NVR between 35Mbps and 75Mbps (not MBps). The cameras are configured for a balance of quality and maximizing the current storage of the NVR. Once I have a lot more storage I will likely dial that up.
That said even if I double that and have 150Mbps inbound from cameras and 50Mbps outbound to the client from the NVR that's nowhere close to what the x4 slot can support. Also I would be limited by what the MB NICs and my switches could support anyway (1Gbps).

So installing the PCIe x8 card in the x4 slot is not an issue at all correct??

 

[popatim]

I wouldnt think it would matter in a quality card but there are probably some cards that break down 4 lanes to each segment. My 9240-8i works fine in an x4 slot.

Which card you you considering?

 

[mlitos]

I wanted to go with an LSI card but the build budget was already more than I wanted. Also not comfortable with some of the 3rd party sellers listing LSI cards for a lot less than reputable sellers. Anyway I went with a High Point card as the price was reasonable:
https://www.amazon.com/dp/B0787JNMDJ/ref=cm_sw_r_other_apa_i_q5WZEbN3P3FH2

 

[popatim]

I've not seen any real reviews of that card but i imagine it will work just fine in an X4 slot.

 

[mlitos]

Thank you again popatim. I found a similar, but older thread elsewhere:

https://superuser.com/questions/334...roller-in-a-x4-electrical-x16-mechanical-slot

A post from one user mentions hes installed several x8 cards in x4 electrical slots and hasn't noticed any issues.