Q: qnap TS-H886 / xeon D-1266 RAM config

[FatherFunky]

hello all (first post)

THREAD CLOSED (unless you know about dual-rank vs single rank)

am planning to order a TS-H886 (intel xeon D1622) after seing this video on youtube “installing truenas on TS-h686”

product page:
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note that there is absolutely ZERO information on the proprietary motherboard.

cpu ARK page:
url removed
cpu mem controler spec: 2133, DDR4, ECC, Dual Channel

I plan to upgrade it to full RAM which is 128G
The usage will be OpenBSD, for ZFS.
note: i will add a pcie Gen3x8 to nvme daughter card, and install the OS there, so that the two integrated nvme slot be available for upgrading the ZFS scheme. (i’m hoping the daughter card will be ok, i chose one that has zero bridge on it on purpose, it basicaly should present the nvme to the motherboard with no problem)
My ZFS usage should be fine with just pumping up the ram to allocate to ZFS, if i need to add nvme or SSD later for L2ARC or SLOG, I will.

by looking at the pics on this review:
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I see that the 16G config (as it’s sold by qnap) has two of these sticks:
TS1GLH72V6B, which google tells me is these:
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specs are: DDR4 ECC 2600 single rank (1Rx8) [[i can’t recall where I got the info “unbuffered” but i’m prety sure they are, if not, please correct me]]

please note the questions are rather agnostic to qnap and has more to do with what the xeon mem controler can do, once it’s presented with four ram slots on its motherboard.

QUESTIONS
1/
can i put in 4 sticks of dual rank, OR, must it beu either 2 sticks of dual rank or 4 sticks of single rank?
2/ (answered: it will run them at 2133)
ARK page says ram max speed is 2133, i can’t find any of these, so I’ll go for 2666, i have never done that before: put higher speed ram on a mem controler. I’m guessing this will go fine since they are DDR4 , which the cpu supports. But i have not found any definitive confirmation on this. will putting 2666 DDR4 ram sticks on a cpu that only support 2133 DDR4 be ok? (note: in the vid we get a very brief look at the bios, and there seems to be no xmp)

.

thank you for reading, and taking the time to answer

have a nice day.

EDIT:formating/typo

[GigaBusterEXE]

It will run them at 2133

[FatherFunky]

thank you for you reply on the speed.

now the gritty part, the first question:
what happens when when using two dual rank ram sticks in the same channel? (in this case that would be a total of 4 dual rank ram sticks)

[FatherFunky]

hey quick update if anyone is interrested:

my question boils down to:
how many ranks per channel does the cpu support?

the question is simple, the answer is not.
after extensive googling i have found only ONE official intel paper that states that each chanel of the cpu can manage “up to 8 ranks”, and it was not on the cpu i’m interrested in.

I have elected to shoot in the dark:

• the cpu supports 128G, the motherboard has only 4 slots.
• 32Gb single rank UDIMMS do exist as per the various ram manufacturers’ spec sheets.
• the 32Gb qnap module does not specify if it’s single or dual rank.

I’ll try 4x 32gb UDIMMS dual rank (meaning 4 ranks per channel)
and hope they are recognized properly. I’ll run a memtest on them first thing.
If not, i’ll try to get a refund, and hunt the internet for two 64gb dual rank modules. (after selling my kidney)