NAS/fileserver project—RP64 in 1U ATX/ITX case (comments welcome!)

[Skirmisher]

Hey all! I was going to just ask a couple questions in the forum, but I decided it'd be better to summarize my project here so I can ask related questions in one place, as they come up.

My partner and I are working to replace an aging Sempron box (FreeBSD 10, some IDE drive for boot, 4x2TB SATA spinning rust in RAID Z) with a RockPro64. We've done gradual planning over time since we got the board many months ago, and most recently I've applied my experience setting up Void Linux on the Pinebook Pro by setting up an install on eMMC for the RP64. At this point the basic system is up and running (with an old Pi 1 hooked up as a serial console), and we have a SATA card and 4x2TB SSDs that work; I've yet to set up ZFS, but other than that, the software side is well on its way.

The remaining tasks are in hardware territory. We have a 12U rack that we'd like to slot this thing into, so putting it in a 1U case seems like the cleanest solution, since we can't stuff 4 drives in the NAS case Pine64 sells. A current contender for the case is this model from plink (we have a 3U case from them already, it's fairly nice), plus a 5.25" caddy for the SSDs. This particular model has the benefit of containing an integrated fan controller, which would save some fiddling with controlling them from the RP64 itself. It's hard to tell, but I believe the controller is powered by a molex connector—which is good news for me, since I can easily adapt that from one of the SATA power connectors for free!

I'm as of yet unsure how I would mount the board in the case; that's what I'm most needing help with. I haven't been able to find any reports of people mounting the RP64 on ATX mounts (if you have, please let me know!). I presumably would need some sort of standoffs, or possibly even a whole riser board. The PCIe card is of course not going to fit on its own in 1U, but since it's solid state I have no qualms getting a riser/extension for it and fastening it wherever is convenient (and has good airflow).

There's also the fair question of power delivery. We of course have the 12V 5A power supply, and that should be plenty to handle these SSDs (5V 1.7A apiece), the fans, and the board itself. It's possible I could set up an ATX PSU like some on here have, and have the power situation a bit more organized, but as that would require cable customization (and the purchase of an extra PSU) I'm not inclined to go that route unless there's some other compelling reason to.

I'm looking forward to getting this project off the ground (read: my desk) in the future! Please let me know if you have any questions, comments, advice, etc.

[kuleszdl]

Hi, how is your interesting project going?

Regarding the mounting of the RP64 board to the ITXATX case: Why not make an adapter plate (metal or 3d printed), screw the RP64 to that and then screw the adapter plate to the case?

Regarding the PCIe card: There are not just static riser cards but also plenty of riser "cables" available, so it should be no problem getting this done.

Another more difficult aspect would be access to ports from the outside. You could attach also extensions here (e.g. for the microSD slot or the USB ports) but it will probably not work with everything. Also connecting the buttons and LEDs could turn out to be a challenge.

One more thing that would be interesting: Which heatsink/fan are you planning to use for the SoC?

[Skirmisher]

Hi kuleszdl! The project has been backburnered for a while, as we haven't ordered a case yet, which kind of holds up the rest of the project.

Having an adapter plate would be ideal, but no one seems to have covered this ground yet for ATX or ITX (although we did find someone who had made 3D-printed parts to mount an RP64 in a Power Mac G4 Cube, which is pretty great haha). We don't have a 3D printer or experience making models for one, but we know people who do, so it's possible we could work this one out on our own.

We're not particularly concerned with making all the I/O accessible, this being a server build. That said, we can cut holes in a generic I/O shield for whichever end of the board we care about being exposed (likely Ethernet and power), and run extension cables if there's anything else that would be nice to have access to outside the case. Could even rig something up to connect the USB2 ports to the front panel header connector.

Power/reset buttons are actually trivial for the RP64, since it has headers for power and reset lines :) LEDs are less concerning, but we could DIY them off GPIO easily enough.

The plan for cooling is to use case fans and have them blow across the 30mm-tall heatsink (already acquired).

[TRS-80]

Regarding the mounting of the RP64 board to the ITXATX case: Why not make an adapter plate (metal or 3d printed), screw the RP64 to that and then screw the adapter plate to the case?

For that matter, why not just use regular standoffs and if necessary, drill another tiny hole or two wherever needed?

I have acquired an entire boxed assortment of them (in different lengths, and including nuts, washers, etc.) off AliExpress for only a few dollars.

EDIT:  Oops, totally forgot to talk about power. 

Since I am planning similar build (although not in rack mount case) I thought I would provide power similar to what I have done for other ARM (Cubietruck) based NAS in the past which is an appropriately sized Mean Well power supply.  Full ATX (or even those little pico ones they sell) are not really appropriate, mainly because we neither have (nor need) the ATX power connector itself.  Cubietruck sold a little add on board to help distribute power, but with the adapters Pine sell in the store (and slightly more DIY), we can accomplish the same thing.

Now, in my case, I am planning 3.5" HDDs, so I calculate power needs more like 8-10A in total for the board and (2) 3.5" HDD.  Which is a little more than you, but overall the planning process is the same.

BTW, I am not sure 5A in your case is "plenty" as I think the ROCKPro64 can use up to 3A by itself, then you have the drives in addition to that.  Well, that is the size power adapter they sell for it, anyway (3A I mean).  I am actually curious what real expected usage is, as that would actually help all of us in planning.

Anyway, turns out in the range I am looking (~9A I figure) these power supplies start to come in 4 pin DIN configuration (at least my preferred Mean Well do) instead of the standard barrel like what was on the Cubietrick (and what is on the ROCKPro64 itself).  I was looking at GST120A Series (GST120A-12 more specifically, which provides 8.5A @ 12V).  Although they have a lot of other models available, too, if you think your power requirements are less.  In fact I already scored 3 of them used off eBay for 60 USD total, shipped (only 20 USD / ea!).    But there are many more and seem to be common and therefore reasonably priced and readily available.

Anyway, so then I ordered some DIN panel mount female plug, for the outside of whatever case I end up using.  I plan then to just solder some (appropriately sized) wires between that plug and into a barrel jack for the board itself, and also into one of the adapters they sell in the store which takes 12V in and puts out the 12V + 5V in a SATA power plug which each drive will need.  Tidying it all up with shrink wrap, etc. of course.

[Skirmisher]

Regarding the mounting of the RP64 board to the ITXATX case: Why not make an adapter plate (metal or 3d printed), screw the RP64 to that and then screw the adapter plate to the case?

For that matter, why not just use regular standoffs and if necessary, drill another tiny hole or two wherever needed?

I have acquired an entire boxed assortment of them (in different lengths, and including nuts, washers, etc.) off AliExpress for only a few dollars.

I'm not super experienced with case mounting, so I haven't done much research in this area (mostly for lack of knowing what to look for).

BTW, I am not sure 5A in your case is "plenty" as I think the ROCKPro64 can use up to 3A by itself, then you have the drives in addition to that.  Well, that is the size power adapter they sell for it, anyway (3A I mean).  I am actually curious what real expected usage is, as that would actually help all of us in planning.

The power supply I'm referring to is this one from Pine, sold as a counterpart to the 3A for heavier power loads, like attaching HDDs. As I stated, our SSDs (Crucial BX500 2TB) are labeled "5V 1.7A", meaning all of them together can theoretically pull 34W, leaving 26W for the rest of the board (assuming a spherical cow maximum efficiency). However, it's unlikely that they will ever pull anything close to 8.5W apiece, more likely living in the sub-watt range being idle most of the time (given NAS usage patterns, i.e. rarely accessed for backup/restore). (This is extrapolated from typical SSD power usage, though, as Crucial's datasheet does not include power consumption statistics. Admittedly, this was not the most thought-out purchase.)

Keep in mind that the "12V 3A" is not just for the board alone, but all peripherals as well. The RK3399 SoC only pulls 6~7W under typical load (according to some TDP numbers out there), with a smattering of draw from other components. People like to attach one or two USB drives to this kind of board, and expect them to work. PCIe devices factor in as well, especially since you might mount an M.2 drive there, or attempt something ridiculous. With those things accounted for, the typical power consumption picture starts to become clearer (for instance, my SATA controller chip is specced to consume a negligible 1W.) However, I haven't measured the board's draw at the wall or looked into its power consumption characteristics, so this is the fidelity of info I can offer.

Anyway, turns out in the range I am looking (~9A I figure) these power supplies start to come in 4 pin DIN configuration (at least my preferred Mean Well do) instead of the standard barrel like what was on the Cubietrick (and what is on the ROCKPro64 itself).  I was looking at GST120A Series (GST120A-12 more specifically, which provides 8.5A @ 12V).  Although they have a lot of other models available, too, if you think your power requirements are less.  In fact I already scored 3 of them used off eBay for 60 USD total, shipped (only 20 USD / ea!).    But there are many more and seem to be common and therefore reasonably priced and readily available.

Anyway, so then I ordered some DIN panel mount female plug, for the outside of whatever case I end up using.  I plan then to just solder some (appropriately sized) wires between that plug and into a barrel jack for the board itself, and also into one of the adapters they sell in the store which takes 12V in and puts out the 12V + 5V in a SATA power plug which each drive will need.  Tidying it all up with shrink wrap, etc. of course.

You might want to note that the 4-pin connector on the RP64 used by Pine's SATA power cable is directly connected to the same line used by the barrel jack, meaning the board can be powered from it as well (taking care to only sink to one of the two power connectors at a time). This is how some people hook up ATX supplies to the board, IIRC. The connector is JST's XH-series (2.5mm pitch), and you could run connectors from some manner of modular power supply to individually power the board and drives (for the sake of flexibility) if you see fit to go beyond 60W.

[kuleszdl]

Please note that the "proper" power supply sold for the RP64 operated as a NAS is 12V 5A, not 12V 3A (which might be fine for the PBP but not for a full NAS). Please also keep in mind that drives need way more power when they spin up compared to when they are already running. Therefore, the power consumption usually reaches its peak when you power on your box...

The 60W PSU could be sufficient for four drives as well - the SoC does not draw that much power in the moment the drives are started (but of course, if you have 100% cpu load and then the drives come back from sleep it could be different).

Imho, my main motivation for fiddling around to get a typical 1U ATX/ITX PSU connected would be more to have everything tidy in the box than to have a more powerful PSU. Also, when using an ATX/ITX PSU I would power the drives directly from there and not through the JST connector on the board since I doubt the board and the connector were designed/tested with such electrical loads in mind.

[Skirmisher]

Please also keep in mind that drives need way more power when they spin up compared to when they are already running. Therefore, the power consumption usually reaches its peak when you power on your box...

I was talking to another person recently who was looking to set up an RP64 NAS with spinning disks, and they suggested staggering the drive spin-up as a way around power limitations. Of course, that requires a bit of ingenuity and isn't suitable for all use cases, but it is at least useful if you want to power off your disks while the board is on and then spin them up again without killing the system.

[TRS-80]

It have been some years since I was looking for a power supply in this range, but last I was (maybe 4-5 years ago, I guess when I was setting up my Cubietruck probably) the smallest ATX supplies available at that time were still hundreds of watts (with the exception of that little pico one).  And when you are that far outside of the intended specs of a power supply, you are going to be using it extremely inefficiently.  I know it's not a big deal in the grand scheme of things, but still.

Also then you have the issue of ATX signalling to turn the power on and off and on which is probably not rocket science but still, just more research and complexity.

For all those reasons, I personally feel that ATX power supply are totally inappropriate for this use case.  But, as you seem bound and determined, go ahead and knock yourself out.  lol  I dunno, maybe you have one "laying around" or whatever that you want to use.  We probably all do.  I personally would still not do that, unless I was extremely strapped for funds.

I would power the drives directly from there and not through the JST connector on the board since I doubt the board and the connector were designed/tested with such electrical loads in mind.

I agree with you here, which was exactly why I had planned to bypass it entirely and just run the drives directly off the main power supply.

-----

EDIT:  There seems to me like a lot of speculation (and a number of variables like startup, etc.) around about proper sizing of power supplies.  Maybe when I get this all working, I post a video or some other data to help others who are DIY their own NAS in the future.

Some more data points in the meantime.  I thought for sure I had posted a link to this already, but there is a post at Armbian about ROCKPro64 as NAS? where I was getting at least some of my estimates from.  FWIW, I plan on eventually adding 2 more 3.5 HDD, for a total of 4.  Estimate in that thread for this use-case was 12V@8A (by soerenderfor).

This is also very close to Helios64 (which actually have 5 (full size) drive bays, but also charge a battery and some other additional things).  But we can use that as yet another data point.  And their power supply is 12V 10A (efficiency : 85%).  In fact I found that info just now on Helios64 Power Consumption section of Kobol Wiki, where they actually list a fair amount of data which I suspect you guys might find interesting.

[kuleszdl]

Thank you for these links!

Yet, I wouldn't say that these kind of power supplies are oversized for this purpose. Recently, I assembled an 1U server using a flex ATX PSU and they start at 100 watts which is exactly the range you are looking at here. For instance, take a look at the models offered by FSP (not a recommendation, just an example):

https://www.fspgroupusa.com/ecommerce/ipc-psu/flex.html

[TRS-80]

It's all coming back to me slowly now. 

Personally, I am pretty particular about power supplies, preferring known and very efficient ones, using that as a rough metric for likely component quality and therefore longevity.  And at the time (and perhaps even now) there were simply none available in this power range.  Maybe that has changed in the meantime.  But I think that's why I got onto those Mean Wells originally, and now never looked back.

Now, this GST120A12-R7B I mentioned above is not the greatest at "88.5%"[0] which makes it something equivalent to like an 80 Plus Gold maybe.  Where I prefer to be well into the 90% efficiency like an 80 Plus Platinum (which is all I buy when building desktop PCs).  But good luck even finding proper and reliable figures from power supply manufacturers, who are well known to outright lie on specs, unless you are dealing with a known vendor.

But I have not looked too hard recently, so if someone finds a nice and efficient power supply from a known vendor, I would be all ears.  When I realized the GST120A12 was "close enough" and a seller accepted my offer for (3) of them (used), shipped, for $60, I jumped on it without a second thought.

[0] And I am not even sure what this really means, as they list it as a "typical" value, instead of an efficiency curve or even values at 25%, 50%, 75% load, etc., hence my "quotes."