3 PCI slots, 3 devices, struggling with 2

[a.dresner]

3 cards, its the HBA and the AOC-SHG3-4M2P

1. Dual 2.5 PCIe 3.1 2.5G i225-v PCI Express 3.1 :5GT/s Support for x1 width
2. HBA 9207-8i PCI 3 x8
3. Supermicro AOC-SHG3-4M2P PCI-E 3.0 x8 (4x Optane for log and meta)

3 Slots
1 PCIe 4.0 x16
1 PCIe 4.0 x4 (in x8 slot) (Supermicro?)
1 PCIe 3.0 x4 (in x8 slot) (NIC)

Obviously the trade off will either be the Optane cache or HBA. With spinning disks, does it make more sense to put the HBA on the slower slot? or the limited amount of data going thru the AOC-SHG3-4M2P warrants it go onto the slower?

 

[ChrisRJ]

Without information about your use-case and how the system behaves under load, I would think that the SSDs should go into the faster slot.

 

[a.dresner]

Mixed use at home server from media storage for Plex to high resolution photos storage, remote file access, Time Machine backups, etc. Probably don't need the cache but like to practice at home before I do it at my office. The office system I just built I plan to use for a Veeam repository and iSCSI target for a windows file server... plan to do similar setup there but motherboard isn't limited like this one.

I'm going to put the HBA on the slower slot, I had asked a similar question earlier in the year and got the same response. Seem to have gone in a circle :D

Another option is I could dump the HBA and put my 6 platters directly to the motherboard? Do I really benefit from having an HBA vs. directly connected to the mobo?

 

[ChrisRJ]

Probably don't need the cache but like to practice at home before I do it at my office.

ZFS does not support cache in the usual sense. SLOG may help, but only for sync writes. L2ARC depends on the workload, but conventional wisdom says that for home use it does not help much (if at all).

Another option is I could dump the HBA and put my 6 platters directly to the motherboard? Do I really benefit from having an HBA vs. directly connected to the mobo?

You will not benefit from an HBA at all. It only draws additional power and needs active cooling, if not used in a rack-mount case with strong airflow.

 

[a.dresner]

ZFS does not support cache in the usual sense. SLOG may help, but only for sync writes. L2ARC depends on the workload, but conventional wisdom says that for home use it does not help much (if at all).

You will not benefit from an HBA at all. It only draws additional power and needs active cooling, if not used in a rack-mount case with strong airflow.

I have enough system memory in both machines so not looking at L2ARC.

Meta Data for speeding up searches and Plex (probably won't see a difference). SLOG for sync writes (at the office more than at home)

Good to know about the HBA at home, will continue to use at the office with is rack mounted in a cool server room.

Really appreciate your feedback. How can I clean up my signatures like you? Show: etc..

 

[ChrisRJ]

Go to https://www.truenas.com/community/help/bb-codes/ and look for "spoiler"

 

[a.dresner]

Go to https://www.truenas.com/community/help/bb-codes/ and look for "spoiler"

Thank you, one of life's mysteries resolved :D