Supermicro H12SSL-i motherboard SATA0-7 sharing PCIE with dual M.2 slots?

[nickwalt]

I'm wondering if I am interpreting this block diagram correctly:



It looks to me like G2 shares lanes between SATA 0-7 and the two M.2 slots - two questions:

1. Is this a correct interpretation?
2. If using this SlimSAS port doesn't interfere with the M.2 slots (which will be populated for ESXi boot [maybe, as this is a modest homelab with a Samsung 980 or 990 Pro SSD I might just go all-in-one Boot/logs/osdata - thoughts appreciated] and OSDATA - ) am I correct in thinking that I can simply connect 8 x SATA JBODs to this SATA 0-7's SlimSAS x8 with this cable, and then pass the entire controller through to a ESXi VM running Truenas?

I figured that using the SlimSAS port would be a more elegant solution than individually populating the 6-8 SATA connectors:



Unfortunately this version of the motherboard doesn't have the LSI 3008 chipset but if using the SlimSAS doesn't interfere with the M.2 slots and it is easy to passthrough to Truenas from ESXi 8 then not having the LSI is moot.

Thanks, appreciated.

 

[mattventura]

That part of the diagram is referring to the SlimSAS 8i connector which can break out to 8 SATA ports or 2 x4 NVMe drives. Those are independent of the 8 individual SATA ports on the board.

G2 has 16 lanes - four for each M.2 slot, then either another four each for 2 more NVMe drives, or one each for 8 more SATA drives. It doesn't "share lanes" in such a way that would bottleneck, it's more like bifurcation.

As for passthrough, I'm not entirely sure how the built-in SATA would handle being passed through. It might work, or it might be stuck in an IOMMU group with other onboard devices. Only way to know for sure is for someone who has this board to check the IOMMU groupings.

 

[vvkvvk]

Both of the SATA controller and NVMe slots on my board sit on their own groups after enabling the options for that in BIOS:

IOMMU Group 59:
46:00.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7901] (rev 51)
IOMMU Group 60:
47:00.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7901] (rev 51)
IOMMU Group 74:
01:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller PM9A1/PM9A3/980PRO [144d:a80a]
IOMMU Group 75:
02:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983 [144d:a808]

 

[nickwalt]

Awesome, thanks for confirming guys. Looks like it's good to go with the SATA drives for Truenas.

This is a good motherboard. Looking forward to building the server when the components arrive.