So while waiting on BlackFriday and hopefully some cheap(er) 8TB-Tosh-N300 disks, for the Primary NAS.
I decided to gather hw. for a Backup NAS, that would inherit the old 4TB drives, from my Primary/Home NAS.
So far i have bought :
2 x Gigabyte MJ11-EC1 Mini-ITX Mainboard
4 x Samsung 32GB 2Rx4 PC4-2666V DDR4 RAM M393A4K40BB2-CTD7Q
2 x SlimSAS (SFF-8654) 4i to SATA breakout cable.
The above price was around 265€
I have a 600W PSU, in the drawer.
Watch out w. the Ram selection , the mobo seems to be “picky”.
This is the “STH Monster thread” about the mobo
I have tested the mobo’s and the Ram.
Bad apple: (Became a Good Apple after a "Enable Clear Bios jumper move)
One Mobo seems to have a working BMC (IPMI), but is doing an endless reboot loop when starting the EPYC. I can’t even get into the BIOS, before it’s rebooting. I have written ram-könig, and asked for a replacement.
Edit Begin
Update on Bad Apple:
I had already tried to reset the BIOS to defaults from the BMC - No Luck.
Then today after being done w. memtests on the other board.
I decided to switch boards again (i just have one spare psu atm.)
I fiddled a bit around, but nothing worked.
The system would never complete the POST, when booting the EPYC.
Then i noticed that the system (BMC) showed that the last Ram installed was a single 16GB Hynix, and that it never detected my Samsung sticks.
I powered totally off, removed the BIOS Battery connector, and set the “Clear BIOS Jumper” to enabled, and waited for 2 minutes …
Now i reverted the Clear BIOS jumper to “normal”, and connected the BIOS battery connector again. .
After powering on , the system behaved diffrently, compared to before.
It was spinning up the EPYC fan.
Waited for a few minutes and started the BMC + Remote KVM viewer.
Improvement … The system wasn’t “Boot looping” anymore , it passed POST , and saw all 64GB of ram.
It booted a few times, loading default bios values & stuff’.
But for the first time I could enter the Real BIOS. 
I changed to boot from usb (memtest86) , and it’s testing now.
I’ll let it finish the memtest, before cancelling the RMA at ram-könig.
Morale:
If you have reboot loop errors on the system, try to “Clear Bios via the jumper”
Load BIOS defaults via BMC Bios access - Doesn’t work in that situation.
Edit End
Good apple:
The other board is working excellent, and has no problems with the Samsung Ram…
A full 4-pass memtest86 took around 9…10h.
While i was at it i measured the powerusage on the 230v side, using the 600W PSU - Not a high efficient i think …
Mobo had the 2 x Samsing Ram + a USB stick (memtest) installed.
BMC/IPMI Only - 7.6W - (BMC runs on 5v stby pwr - Psu wasn’t “real” on)
Running memtest (4 cores no HT) - 68…70W
The other 2 “Ram sticks” did all 4-passes too wo. errors, and was why i think the “Bad-apple” mobo is defective.
I have not begun to use the Primary NAS yet 
As i hope that BlackFriday might give good offer on some (6 x 8TB Tosh-N300) , then i have 6 for the primary , and one in “spare”.
Master Plan for making my Backup NAS:
Install new 8T disks in Primary.
Get a Node 304 chassis.
Install Mobo + PSU.
Install a 256GB Boot NVME
Move the 5 x 4-TB disks to Backup NAS.
Q1:
Since i’d like to run RaidZ2, i need another 4-TB
I have a 4-TB WD Purple (Video), w. 4…6 weeks running time, can i use that one as the 6’th disk ?
Q2:
Will my 32GB Sticks -
Samsung 32GB 2Rx4 PC4-2666V DDR4 RAM M393A4K40BB2-CTD7Q
Function in my Primary NAS mobo : X10SDV-6C+ -TLN4 ?
I don’t have much experience w. ECC Ram.
Q3:
Does anyone here use the : Gigabyte MJ11-EC1 Mini-ITX Mainboard
And have some working Bios/BMC update files i can get ?
@etorix … hint…hint 
My current version on the “Good-apple” is:
I would love to get some hints/tips for the mobo , and settings.
Please don’t just point me to the 25 pages STH thread, if possible.
Q5:
I don’t have a 3-D printer.
I’ll try to see if i can get one printed in DK.
But if not:
Can anyone (EU) print me an IO-Shield ?
Or point me to a place where i can get one for a “reasonable price” (EU).
Q7:
I haven’t enabled CPU (hyper) threading yet.
Someone on YT mentioned that the performance actually got worse, when doing that (mumbled memory bw). If i just run the Box as NAS wo. any APPS installed. Will TrueNAS benefit from 4c/8t vs plain 4c.
Q8:
I was considering the Jonsbo N3 chassis.
But think i read that the Node 304 had much better HDD cooling, is that correct ?
Q9:
Maybe someone knows the below, before i waste time digging.
Can a Node 304 be used w. a Mini-ITX mobo ?
Can a Node 804 ?
That’s it for now …
Ohh - I got two MoBo’s to have a spare, while they have.
TIA
Bingo
).