Build Report: Norco RPC-431

[Constantin]

Hi everyone,

As you may recall, I have been casting about for a replacement to my Mini XL case, which is just a little too restrictive re: air flow for the HGST drives I like using. Using default BIOS settings, the HGSTs hit 50*C during scrubs and even normal operations keep them toasty.

A upgrade to a more powerful 120mm fan in the rear (thank you, Robert12!) helped things somewhat. Now the drives only hit 40*C during scrubs, but that still will not help drive longevity. So, I first bought a NZXT H440, as it has lots of internal drive space (11x3.5"!). But I don't like the piggy-back hard drive mounting system or the lack of an space between the front fans and the drives. The case may make a good hackintosh case some day, however.

On the surface, the Norco RPC-431 looks like a pretty good compromise regarding air flow, disk capacity, size, etc. It's basically a short 4U server, with two beefy handles up front, a perforated intake, etc. Where it differs is the depth and in that it uses a standard ATX power supply instead of the skinny ones that supermicro and iX like to use.

In the following posts, I go over what I tried to make this case work. However, I'll cut to the chase by concluding that this Norco product is a terrible candidate for a FreeNAS server. Besides the filled hard drive rack interfering with my ATX power supply (i.e. you cannot lower the rack once the drives are in place), I also question the design intent where there is no space between hard drives once they have been installed in the rack. Basically, your 3x3 array of 3.5" hard drives would only be cooled from the front and to some limited extent (based on which drive we're looking at) from the sides. Particularly the drive in the center of that array would likely get toasted during a scrub.

So... you have been warned. Below then, my journey begins.

The case came in a fairly bomb-proof double cardboard box with plenty of polystyrene and a plastic bag around the case. The case is steel and features a protective plastic layer (LDPE?) on much of it.


The top is held in place with four screws as well as two depressable latches. I'm inclined to toss the screws and just rely on gravity and the latches going forward. Here is a shot of the underside of the cover, illustrating the latches.


Installation instructions are non-existent. Norco has nothing on their site either. Besides the case, the only thing inside the box are these drive sled runners. These are affixed with screws to the hard drives, then the sleds are clicked into the case.


Underneath the cover, there is plenty of room for a mini ITX board like the C2750D4I found in the Mini XL. There is room for two 80mm fans in the rear to complement the two 120mm fans already installed in the front. The sheet metal you see in the front/top is the HDD cage, which is non-removable, unless you enjoy drilling out rivets.

Based on past experience, I want to ensure better air flow and no re-circulation through the front. I'll remove the two OEM fans in favor of three Noctua PWM models... question is whether those will fit... the drive cage rotates so closely to the front fans that the corner of the HDD cage touches the OEM fan bodies as it rotates. Thus, if the Noctuas are deeper than OEM, I'm out of luck.

Electrically speaking, two of those fans would be attached to the two front fan headers on the motherboard, the center one will be attached to CPU fan header #1. With some ducting on the underside of the enclosure, the air flow should be fairly shared between the three hard drive stacks. The center stack would then direct its flow right over the motherboard CPU heat sink.


The case advertises room for a 2.5" drive as well, a bracket for which you can see on the underside of the drive tray once you rotate it up. Six screws fix the rotating tray until you remove them. I'm inclined to leave them aside as well.


Not sure what those silicone grommets on the 2.5" bracket are for but presume they have to do with isolating a 2.5" drive? The whole lack of documentation gets a bit old when it comes to figuring out details like this one. In this regard, the guides that iXsystems publish are light years ahead - easy to follow, thorough, and nicely illustrated.

Unlike the mini XL, the 3.5" drives are not easily hot-swappable. Plus, there is no backplane for them to click into. Instead, you will have to hook up nine drives worth of hard drive cables, which can easily create a rats nest. Unfortunately, cable management is non-existent as well. Accommodating the rotating cage potentially presents some trouble.

Overall, I think this case is a good value thus far as it's available for about $80. Besides the fan upgrade, I'm also looking into shaping the air flow with a fiberglassed insert (much like SuperMicro does much more elegantly with some see-through plastic in their larger 4U enclosures). In my next entry, I'll detail the installation process.

The case has some very rough edges, however. Other reviewers noted issues with tolerances, such as screw holes for rack glides being in the wrong places. Can't comment on that (won't be using rack glides) but several screws stood proud, either because they were cross-threaded or the metal sheets below did not align. Either bothers me as misalignments and cross-threadings invariably lead to stripped screws.

 

[Constantin]

So, took off the front to have some fun with the front cooling fans. Tool-wise, I am a little resource constrained at the moment but hope to remedy that soon by bringing the unit to the lab.

First of all, let's take a quick look at that front panel. Below are pictures of the connectors for several indicator lights, including Power, activity lights for 3 NICs, and "Alarm". There are two momentary buttons, one for power, the other for reset. One USB3 as well as one USB2 connector round out the front panel. Thus, given my C2750D4I motherboard, I will cover the front USB3 connector with the plug Ixsystems supplies for one of the rear USB ports and then change the jumpers on the motherboard to activate both rear USB 2.0 ports.



To remove the front fascia, mounting plate and fans, you simply have to remove a bunch of tiny screws on the top and bottom of the front frame corner. The handle brackets can stay in place. The front fascia consists of a thin, perforated piece of sheet metal with a sliver of HEPA filter material underneath. The holes in the fascia are tiny and I expect that they will produce some static pressure drop.



Behind the fascia is a mounting plate that everything in the front attaches to. The black fascia uses one 1 screw to attach to the mounting plate, the fans use three bolts each. The picture below shows the two fans lying on the mounting plate, I show one upside-down so you can enjoy trying to decipher the source. Nothing special there, just 120mm fans with 3-pin connectors. The mounting plate only comes pre-punched for 2 fans. Thus, if you want to retrofit a trio, you will have to drill some mounting holes.



Because I'm a bit OCD regarding air flow, here is a mock-up of what the three front fans will eventually look like. Unfortunately, the third Noctua is currently inside the Mini XL case, so one of the OEM fans had to stand in for the picture. The other perspective shows one fan mounted and the three larger holes I eventually plan on cutting into the mounting plate with my Dremel tool. My final pattern will likely leave more "meat" at the edges as this mounting plate also adds to the structural integrity of the case. I am mounting the fans high up as my primary concern are the hard drive temperatures.



These larger holes will then be covered with fan guards that will hopefully maximize air flow compared to the present arrangement. A Newegg reviewer noted that he/she was able to install a pair of 140mm fans which seems plausible as long as you drill your own holes. The 140mm fans could be desirable because they cover more of the front opening (about 6.5" tall) than the 120mm fan. That in turn would put more air on your motherboard. While adding three 140mm fans might be possible (the mounting plate is a bit over 16.5" wide), I wonder if the third fan would interfere with the status lights, USB, power switch, etc. board. Plus, finding "meat" to screw into can be hard because of the perforation holes in the mounting plate. Two 140mm fans and a 120mm fan seems like a safer bet, from an interference and mounting point of view.

In an ideal world, I'd add a thin piece of sheet metal to the mounting plate with holes in the right places to increase its rigidity and reduce air leakage past the fans. For now, remaining pre-existing holes in the sheet metal will be covered with duct tape, as I want to minimize re-circulation through the front panel and focus the flow towards the rear of the unit. The HEPA foam layer will likely make a comeback, not so sure about the perforated sheet metal cover. One option for the front cover might be to hole-saw an opening for each fan, ruining the sleek look but also improving the air flow.

Next, I will repurpose some shipping boxes to mock-up the air flow vanes I plan on adding to the case so that the air goes where I need it. The mock-ups will then be used as a mold for some fiberglass I have left over from previous projects. Holes in the rear not associated with fans (PCIe covers, etc.) will be blocked off to focus the airflow to the areas that I care about.

The rear fans were relatively easy to install, though the Noctua 80mm PWM models are a TIGHT fit. There was quite a bit of resistance to getting them in. One nice feature are the extension, splitter, etc. cords that Noctua furnishes, they make installing these fans much easier. Between the two fans in the back along with the ATX power supply and the three fans up front, there will be 6 fans inside the unit.



Hopefully, when all is said and done, this rig will run cooler than my current HGST / Mini XL hard drive toaster. My final rig may even evolve further to feature a single 140mm fan in the center (to direct more air flow to the mini ITX motherboard) while keeping the two 120mm fans on the sides.

 

[Constantin]

OK, short update tonight as the weekend up North has been a bit stressful. With unseasonably cold temperatures for a week straight, I've been out and about helping friends repair their heating systems. Ours has thankfully held up thus far.

Anyhow, tonight I may have finalized the front plate for the Norco RPC-431. First, I measured out where to put the fans, added the mounting holes, then went to town with a dremmel tool to remove excess sheet metal (see mounting plate above for 'before' state).

On further reflection after my last post, I added a 140mm fan in the center to direct more air flow to the motherboard. Adding that fan was not easy due to hole alignment issues, i.e. where to find a spot where there is metal to drill into for the mounting screws. Thankfully, the fan grill I also ordered actually made mounting much easier, as it helps clamp the fan in place.



Thanks to fan frames and fan guards, the mounting plate is still surprisingly stiff despite the large holes and all the missing metal. Then covered the remaining mounting plate holes with duct tape on both sides to seal and limit recirculation through the front fascia. The left picture shows a 'during' picture from the front of the assembly (i.e. the duct tape is being put in place) the right picture shows the back 'after' adding the duct tape.

Tomorrow, I hope to put together the air duct under the hard drive cages. Cheers and good night.

 

[Constantin]

OK, finished the air duct to direct air past the drive cages and from there to the CPU cooler. Used some leftover XPS and a hot knife to form these. Some spray adhesive holds it all in place before I use screws to permanently secure. Big hole in the middle is meant to divert more air over the CPU cooler, which would be mounted behind this purple ridge. In the unused back corner, another foam piece diverts flow towards the remaining two PCIe covers, only one of which will be in use.



Time to put the front cover back together, doesn't look too bad. Naturally, the screws don't quite line up, but that was kind of to be expected, considering that 3/4 of them looked cross-threaded when I got the case.



Started to load up the hard drives and learned that I got hornswaggled, part 1: Note the lack of distance between the two drives. The whole reason to go with this case in the first place was better ventilation than the Mini XL. But Norco evidently wants to be best in class re: delivering a hard drive toaster. Particularly the drive at the center of the array will only experience some cooling on its front face. All other surfaces are practically insulated from good air flow.


So that wasn't going to work. Removed the pink stuff below the hard drive cage and sited three drives there using metal standoffs and high-quality velcro tape. That way, I could leave a significant gap between the hard drives in the cages, and the drives down below would serve the same function as the ridge and cover the fan wires, front panel wiring, etc. too.



Now came the really frustrating part. It is completely evident how little consideration cable management had at Norco during the design process. There are no mounting points for zip tes, no channels, nothing. Basically, you have a great invitation to a spaghetti party. All this spaghetti has to hang from something, so you either modify the case (i.e. lots of drilling to create holes for zip ties) or you risk damaging the connectors on the backs of your hard drives due to the leverage that all those cables exert.

I soldiered on, making all the connections and discovering at the end that I could no longer close the hard drive cage once the cages were populated *and* the cables were in place. Basically, the power supply is too long, the plugs coming out of the hard drives and the plugs stuck into the power supply interfere with each other.


This is the corner of the ATX interfering with the hard drive SATA power connector. This is unfixable unless I get a much smaller power supply.

 

[Constantin]

TL;DR: The Norco RPC-431 is a stinker of a case.

Exclusive users of 2.5" drives might find the case tolerable on account of better airflow around their drives than the 3.5" drives it was allegedly built for.

Anyone contemplating putting more than six 3.5"drives into this case will likely need to use low-power versions that produce little heat. Even so, I doubt the drives will not exceed 50*C on a scrub, as there is maybe a 1-2mm gap between drives. Worse, the plastic runners that Norco uses are so badly engineered that one drive is now stuck inside the rotating drive cage. Needless to say, I am not impressed.

Cable-salad issues will haunt you, regardless of how many drives you add. Norco doesn't offer SATA backplanes like Lian Li, so there will be lots of cables needed and no mounting points to keep them organized. Avoiding a rats nest will require you to be proficient with confectioning your own cable assemblies, especially on the power side.

This issue is made all the worse by the rotating drive assembly / cage as your hard drive cables will have to be long enough to reach their designated spots whether the cages are up or down. All that slack means just more cable that the case has to swallow and digest somewhere. Consider the leverage that unsupported cable assemblies will put on your hard drive connectors. You can easily damage them!

On top of that, the case is built frustratingly cheap. For example, removing a PCIe slot cover pretty much requires a grinder / dremmel because the meat still holding on the covers is so thick and wide that the usual removal method will bend the case. Similarly, the Noctua 80mm rear fans got totally squished on installation and constantly wanted to pop out.

If the designers had simply opted for a different mounting method, perhaps they could have designed a case that allows for good airflow and copious hard drive capacity. But this design seemed to be too focused on accommodating a wide variety of motherboard sizes rather than focusing on the hard drives, despite including room for 10 drives (9x 3.5", 1x 2.5").

A simple sideways slot loader would easily allow the same number of hard drives to be accommodated while also allowing better airflow and the use of bog-standard power cables. Granted, the case would only allow the use of a mini-ITX motherboard form factor but at least it would work. If I had more time and access to a 3D printing shop I may have attempted to build such a contraption but no can do.

A fold out front panel would go a long way to make fan maintenance and hard drive access easier without the need for a rotating drive cage. Better hard drive mounting options exist than the sleds that Norco likes using.

This case has wasted enough of my time. It will be recycled soon, hopefully to be reborn as something useful.

 

[Sphinxicus]

Thanks for the great amount of detail in this build report. I was looking at the very same case as you due to depth restrictions in my rack. I wouldn't have given lack of space between disks a thought since i would have assumed that any reputable case designer would want to provide adequate airflow around the disks...

I have been looking for a short depth rackmount case that fits my needs (multiple drive capacity, short depth, ATX power supply, not limited to mini-atx mobo for some time and i think i'm coming to the conclusion that i need to think about relocating where this NAS will sit to either a tower case or a new deeper rack. Either way, i will be avoiding this case now and probably Norco too since they don't seem to be creating products with love :P

 

[Constantin]

A reputable case designer / seller shows the hard drives in place... so you can visualize how "stuffed" the array is. But if I lacked morals and my sole intent was to sell lots of these cases, I would NEVER show the drives in place. At this price point, few customers will try to return the case after discovering just how cramped the hard drive cage really is.

For the Norco RPC-431, the design intent evidently was maximizing the floor area of the case and the available height under the hard drive cage. This dogged design intent accommodates a wide variety of motherboards at the expense of minimizing air flow paths around the hard drives.

If you dropped any motherboard support for boards deeper than 7" you could ditch the cage, mount the drives standing up on their sides with the long axis oriented to the rear of the case, and still have room for an air duct beneath them. More importantly, you'd be able to mount a backplane to reduce cable clutter and minimize interference opportunities with the power supply.

Some semblance of a manual (that details, for example, the allowable maximum length of a power supply) would be another worthwhile addition.

 

[ShimadaRiku]

Looks the the front panel can be removed as well as the 9xHDD cage.

Do you think the Norco RPC-431 with some modding would fit three 5in3 hotswap cages?

 

[Constantin]

The cage might be removable as long as you are comfortable drilling out rivets. IIRC, there are one or three per side.

I would review the sparse documentation very carefully re: fitting anything in there. Adding hotswap cages is a brilliant idea, provided you still have enough space for the motherboard and cabling. Some of the motherboard standoffs may also need to be removed. A 4.5” grinder should do the trick.

You may or may not have to add something to hold the case together once the extant cages are removed, without the front and the back the thing might distort in a heartbeat despite the heavy gauge of the case metal used.

Unfortunately, my case met its end in the recycling bin a long time ago, so I can’t help you re measurements, sorry! But the pictures might give you a clue given that the fan dimensions are known.

Good luck and I note the irony that you’ll likely spend more on the hot swap cages than the case.

 

[ShimadaRiku]

Good luck and I note the irony that you’ll likely spend more on the hot swap cages than the case.

Yea, a single hot swap cage is the same price as the entire case & I need 3x. Never really understood why those cages cost so much.

 

[Constantin]

What sunk it for me was the inadequate space between the back of a standard ATX power supply and the cages. You might need to go SFX with a bracket to gain the necessary room.

Given that the cost of a used known good supermicro 836 is about the same as this proposed project, I’d go the known-good used route. But understand that not everyone is a fan of the noise and size of a supermicro case before upgrades.